This is difference between the default preference of Firefox 70.0 beta 10 and one of 69.0.1. This diff table is generated with my small script firefox-prefjs-surveyer.

Preference difference
PrefFirefox 69.0.1Firefox 70.0 beta 10
abc.def true undefined
app.releaseNotesURL https://www.mozilla.org/%LOCALE%/firefox/%VERSION%/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-browser&utm_campaign=whatsnew https://www.mozilla.org/%LOCALE%/firefox/%VERSION%beta/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-browser&utm_campaign=whatsnew
app.update.channel release beta
app.update.url.details https://www.mozilla.org/%LOCALE%/firefox/notes https://www.mozilla.org/%LOCALE%/firefox/beta/notes
app.update.url.manual https://www.mozilla.org/firefox/ https://www.mozilla.org/firefox/beta
apz.allow_immediate_handoff true false
apz.gtk.kinetic_scroll.enabled false true
apz.overscroll.spring_friction 0.015 undefined
apz.overscroll.spring_stiffness 0.0018 undefined
browser.cache.cache_isolation undefined false
browser.cache.compression_level 0 undefined
browser.cache.frecency_experiment 0 undefined
browser.cache.memory.capacity undefined -1
browser.contentblocking.allowlist.annotations.enabled true undefined
browser.contentblocking.allowlist.storage.enabled true undefined
browser.contentblocking.customBlockList.preferences.ui.enabled undefined false
browser.contentblocking.features.strict tp,tpPrivate,cookieBehavior4,cm,fp tp,tpPrivate,cookieBehavior4,cm,fp,stp
browser.contentblocking.introCount 0 undefined
browser.contentblocking.introDelaySeconds 1800 undefined
browser.contentblocking.maxIntroCount 0 undefined
browser.contentblocking.rejecttrackers.control-center.ui.enabled true undefined
browser.contentblocking.rejecttrackers.reportBreakage.enabled true undefined
browser.contentblocking.report.cookie.url undefined https://support.mozilla.org/1/firefox/%VERSION%/%OS%/%LOCALE%/cross-site-tracking-report
browser.contentblocking.report.cryptominer.url undefined https://support.mozilla.org/1/firefox/%VERSION%/%OS%/%LOCALE%/cryptominers-report
browser.contentblocking.report.fingerprinter.url undefined https://support.mozilla.org/1/firefox/%VERSION%/%OS%/%LOCALE%/fingerprinters-report
browser.contentblocking.report.lockwise.enabled undefined true
browser.contentblocking.report.lockwise.how_it_works.url undefined https://support.mozilla.org/1/firefox/%VERSION%/%OS%/%LOCALE%/password-manager-report
browser.contentblocking.report.lockwise.url undefined https://lockwise.firefox.com/
browser.contentblocking.report.manage_devices.url undefined https://accounts.firefox.com/settings/clients
browser.contentblocking.report.monitor.enabled undefined true
browser.contentblocking.report.monitor.how_it_works.url undefined https://support.mozilla.org/1/firefox/%VERSION%/%OS%/%LOCALE%/monitor-faq
browser.contentblocking.report.monitor.sign_in_url undefined https://monitor.firefox.com/oauth/init?entrypoint=protection_report_monitor&utm_source=about-protections&email=
browser.contentblocking.report.monitor.url undefined https://monitor.firefox.com/?entrypoint=protection_report_monitor&utm_source=about-protections
browser.contentblocking.report.proxy.enabled undefined false
browser.contentblocking.report.proxy_extension.url undefined https://private-network.firefox.com/
browser.contentblocking.report.social.url undefined https://support.mozilla.org/1/firefox/%VERSION%/%OS%/%LOCALE%/social-media-tracking-report
browser.contentblocking.report.tracker.url undefined https://support.mozilla.org/1/firefox/%VERSION%/%OS%/%LOCALE%/tracking-content-report
browser.contentblocking.reportBreakage.enabled false undefined
browser.contentblocking.trackingprotection.control-center.ui.enabled true undefined
browser.fixup.typo.scheme undefined true
browser.in-content.dark-mode false true
browser.messaging-system.fxatoolbarbadge.enabled undefined true
browser.messaging-system.whatsNewPanel.enabled false true
browser.newtabpage.activity-stream.asrouter.providers.whats-new-panel undefined {"id":"whats-new-panel","enabled":true,"type":"remote-settings","bucket":"whats-new-panel","updateCycleInMs":3600000}
browser.newtabpage.activity-stream.discoverystream.enabled false true
browser.safebrowsing.provider.mozilla.lists base-track-digest256,mozstd-trackwhite-digest256,content-track-digest256,mozplugin-block-digest256,mozplugin2-block-digest256,block-flash-digest256,except-flash-digest256,allow-flashallow-digest256,except-flashallow-digest256,block-flashsubdoc-digest256,except-flashsubdoc-digest256,ads-track-digest256,social-track-digest256,analytics-track-digest256,base-fingerprinting-track-digest256,content-fingerprinting-track-digest256,base-cryptomining-track-digest256,content-cryptomining-track-digest256,fanboyannoyance-ads-digest256,fanboysocial-ads-digest256,easylist-ads-digest256,easyprivacy-ads-digest256,adguard-ads-digest256 base-track-digest256,mozstd-trackwhite-digest256,content-track-digest256,mozplugin-block-digest256,mozplugin2-block-digest256,block-flash-digest256,except-flash-digest256,allow-flashallow-digest256,except-flashallow-digest256,block-flashsubdoc-digest256,except-flashsubdoc-digest256,ads-track-digest256,social-track-digest256,analytics-track-digest256,base-fingerprinting-track-digest256,content-fingerprinting-track-digest256,base-cryptomining-track-digest256,content-cryptomining-track-digest256,fanboyannoyance-ads-digest256,fanboysocial-ads-digest256,easylist-ads-digest256,easyprivacy-ads-digest256,adguard-ads-digest256,social-tracking-protection-digest256,social-tracking-protection-facebook-digest256,social-tracking-protection-linkedin-digest256,social-tracking-protection-twitter-digest256
browser.search.separatePrivateDefault undefined false
browser.security.newcerterrorpage.mitm.enabled true undefined
browser.tabs.remote.force-paint undefined true
browser.tabs.remote.useCrossOriginEmbedderPolicy undefined false
browser.tabs.remote.useCrossOriginPolicy false undefined
browser.urlbar.megabar undefined false
browser.urlbar.quantumbar true undefined
content.cors.disable undefined false
content.notify.backoffcount undefined -1
content.notify.interval undefined 120000
content.notify.ontimer undefined true
content.sink.enable_perf_mode undefined 0
content.sink.event_probe_rate undefined 1
content.sink.initial_perf_time undefined 2000000
content.sink.interactive_deflect_count undefined 0
content.sink.interactive_parse_time undefined 3000
content.sink.interactive_time undefined 750000
content.sink.perf_deflect_count undefined 200
content.sink.perf_parse_time undefined 360000
device.sensors.test.events undefined false
devtools.aboutdebugging.new-enabled true undefined
devtools.browserconsole.input.editorWidth undefined 0
devtools.browsertoolbox.fission undefined false
devtools.connectpage.enabled undefined false
devtools.debugger.component-visible true false
devtools.debugger.dom-mutation-breakpoints-visible undefined false
devtools.debugger.event-listeners-visible true false
devtools.debugger.expressions-visible true false
devtools.debugger.features.async-stepping true false
devtools.debugger.features.dom-mutation-breakpoints undefined true
devtools.debugger.features.inline-preview undefined false
devtools.debugger.features.overlay-step-buttons undefined false
devtools.debugger.features.windowless-workers true undefined
devtools.debugger.workers-visible true false
devtools.debugger.xhr-breakpoints-visible true false
devtools.inspector.inactive.css.enabled false true
devtools.markup.mutationBreakpoints.enabled false true
devtools.netmonitor.features.resizeColumns true undefined
devtools.netmonitor.features.search undefined false
devtools.netmonitor.panes-search-height undefined 450
devtools.netmonitor.panes-search-width undefined 550
devtools.netmonitor.ws.displayed-frames.limit undefined 500
devtools.netmonitor.ws.messageDataLimit undefined 100000
devtools.netmonitor.ws.payload-preview-height 450 128
devtools.netmonitor.ws.payload-preview-width 550 undefined
devtools.netmonitor.ws.visibleColumns undefined ["data", "time"]
devtools.onboarding.experiment off undefined
devtools.onboarding.experiment.flipped false undefined
devtools.onboarding.telemetry.logged false undefined
devtools.popup.disable_autohide undefined false
devtools.recordreplay.logging undefined false
devtools.recordreplay.loggingFull undefined false
devtools.storage.extensionStorage.enabled undefined false
devtools.toolbox.content-frame undefined true
devtools.toolbox.force-chrome-prefs undefined true
devtools.webconsole.input.editorOnboarding undefined true
devtools.webconsole.input.editorWidth undefined 0
devtools.webconsole.jsterm.codeMirror true undefined
devtools.webide.enabled true false
dom.allow_XUL_XBL_for_file undefined false
dom.block_reload_from_resize_event_handler undefined true
dom.capture.enabled undefined false
dom.enable_window_print undefined true
dom.events.dataTransfer.protected.enabled undefined false
dom.events.user_interaction_interval undefined 5000
dom.forms.number.grouping undefined false
dom.ipc.cancel_content_js_when_navigating false true
dom.ipc.cpows.log.enabled undefined false
dom.ipc.cpows.log.stack undefined false
dom.ipc.processPrelaunch.delayMs undefined 1000
dom.ipc.processPriorityManager.backgroundGracePeriodMS undefined 0
dom.ipc.processPriorityManager.backgroundPerceivableGracePeriodMS undefined 0
dom.ipc.processPriorityManager.enabled undefined false
dom.ipc.processPriorityManager.testMode undefined false
dom.ipc.tabs.disabled undefined false
dom.largeAllocation.testing.allHttpLoads undefined false
dom.maxtouchpoints.testing.value undefined -1
dom.min_tracking_background_timeout_value 4 undefined
dom.min_tracking_timeout_value 4 undefined
dom.quotaManager.loadQuotaFromCache undefined true
dom.quotaManager.temporaryStorage.chunkSize undefined 10240
dom.quotaManager.temporaryStorage.fixedLimit undefined -1
dom.script_loader.external_scripts.utf8_parsing.enabled false true
dom.securecontext.whitelist_onions undefined false
dom.security.respect_document_nosniff undefined true
dom.storage.abort_on_sync_parent_to_child_messages undefined false
dom.storage.next_gen false true
dom.testing.sync-content-blocking-notifications undefined false
dom.w3c_pointer_events.multiprocess.android.enabled undefined true
dom.webidl.test1 undefined true
dom.webidl.test2 undefined true
dom.webnotifications.allowcrossoriginiframe undefined false
dom.window.history.async undefined true
dom.worker.script_loader.utf8_parsing.enabled false true
dom.xhr.lowercase_header.enabled true undefined
editor.password.mask_delay undefined -1
editor.password.testing.mask_delay undefined false
extensions.getAddons.discovery.api_url https://services.addons.mozilla.org/api/v4/discovery/?lang=%LOCALE% https://services.addons.mozilla.org/api/v4/discovery/?lang=%LOCALE%&edition=%DISTRIBUTION%
extensions.webcompat-reporter.enabled false true
geo.timeout undefined 6000
gfx.blocklist.all undefined 0
gfx.core-animation.enabled undefined false
gfx.font_ahem_antialias_none false undefined
gfx.font_rendering.ahem_antialias_none undefined false
ghi.jkl true undefined
identity.fxaccounts.service.monitorLoginUrl undefined https://monitor.firefox.com/
identity.fxaccounts.service.sendLoginUrl undefined https://send.firefox.com/login/
idle_period.during_page_load.min undefined 12
idle_period.min undefined 3
javascript.options.baselinejit.threshold 10 100
javascript.options.bigint true undefined
javascript.options.blinterp undefined true
javascript.options.blinterp.threshold undefined 10
javascript.options.gc_delay undefined 4000
javascript.options.gc_delay.first undefined 10000
javascript.options.gc_delay.full undefined 60000
javascript.options.gc_delay.interslice undefined 100
javascript.options.mem.gc_allocation_threshold_factor 90 undefined
javascript.options.mem.gc_allocation_threshold_factor_avoid_interrupt 90 undefined
javascript.options.mem.gc_allocation_threshold_mb 30 27
javascript.options.mem.gc_avoid_interrupt_factor undefined 100
javascript.options.mem.gc_non_incremental_factor undefined 112
javascript.options.mem.high_water_mark 128 undefined
javascript.options.unboxed_objects false undefined
layers.compositing-tiles.height undefined 1024
layers.compositing-tiles.width undefined 1024
layers.d3d11.enable-blacklist undefined true
layout.css.aspect-ratio-number.enabled undefined false
layout.css.devPixelsPerPx -1.0 -1
layout.css.paint-order.enabled true undefined
layout.css.shared-memory-ua-sheets.enabled false true
layout.css.text-decoration-skip-ink.enabled false true
layout.css.text-decoration-thickness.enabled undefined true
layout.css.text-decoration-width.enabled false undefined
layout.css.text-underline-offset.enabled false true
layout.css.use-counters-unimplemented.enabled undefined false
layout.float-fragments-inside-column.enabled true undefined
layout.framevisibility.amountscrollbeforeupdatehorizontal undefined 2
layout.framevisibility.amountscrollbeforeupdatevertical undefined 2
layout.reflow.synthMouseMove undefined true
layout.show_previous_page undefined true
layout.viewport_contains_no_contents_area undefined false
mathml.deprecated_style_attributes.disabled undefined false
mathml.legacy_number_syntax.disabled undefined true
mathml.mathsize_names.disabled undefined false
mathml.mathspace_names.disabled undefined false
mathml.mfrac_linethickness_names.disabled undefined false
mathml.nonzero_unitless_lengths.disabled undefined true
media.audioFocus.management undefined false
media.audioipc.pool_size 2 1
media.cloneElementVisually.testing undefined false
media.mediacapabilities.drop-threshold undefined 95
media.mediacapabilities.from-database undefined true
media.mediasource.webm.enabled true false
media.peerconnection.ice.obfuscate_host_addresses undefined false
media.peerconnection.ice.proxy_only_if_behind_proxy undefined false
media.peerconnection.mtransport_process undefined false
media.rdd-opus.enabled undefined true
media.rdd-wav.enabled undefined true
media.webrtc.net.force_disable_rtcp_reception undefined false
media.webrtc.platformencoder undefined false
network.dns.disablePrefetchFromHTTPS undefined true
network.dns.skipTRR-when-parental-control-enabled undefined true
network.http.altsvc.proxy_checks undefined true
network.http.referer.defaultPolicy.trackers 3 2
network.http.referer.referrerLengthLimit undefined 4096
network.http.sendOriginHeader 0 2
network.http.spdy.bug1556491 undefined true
network.http.spdy.bug1563695 undefined true
network.netlink.route.check.IPv4 undefined 23.219.91.27
network.netlink.route.check.IPv6 undefined 2a02:26f0:40::17db:5b1b
network.trr.request-timeout 1500 undefined
network.trr.request_timeout_mode_trronly_ms undefined 30000
network.trr.request_timeout_ms undefined 1500
page_load.deprioritization_period undefined 5000
permissions.desktop-notification.notNow.enabled undefined false
permissions.fullscreen.allowed undefined false
privacy.firstparty.isolate.block_post_message undefined false
privacy.fuzzyfox.clockgrainus undefined 100
privacy.reduceTimerPrecision.unconditional undefined true
privacy.resistFingerprinting.target_video_res undefined 480
privacy.restrict3rdpartystorage.console.lazy undefined true
privacy.socialtracking.block_cookies.enabled undefined true
privacy.socialtracking.notification.counter undefined 0
privacy.socialtracking.notification.enabled undefined true
privacy.socialtracking.notification.lastShown undefined 0
privacy.socialtracking.notification.max undefined 2
privacy.socialtracking.notification.period.min undefined 172800000
privacy.socialtracking.notification.session.pageload.min undefined 4
privacy.trackingprotection.cryptomining.annotate.enabled true undefined
privacy.trackingprotection.fingerprinting.annotate.enabled true undefined
privacy.trackingprotection.introURL https://www.mozilla.org/%LOCALE%/firefox/%VERSION%/content-blocking/start/ undefined
privacy.trackingprotection.socialtracking.annotate.enabled false undefined
security.aboutcertificate.enabled undefined false
security.all_resource_uri_content_accessible undefined false
security.allow_eval_in_parent_process undefined false
security.allow_eval_with_system_principal undefined false
security.block_Worker_with_wrong_mime undefined false
security.block_ftp_subresources true undefined
security.identityblock.show_extended_validation undefined false
security.insecure_connection_icon.enabled false true
security.insecure_connection_icon.pbmode.enabled false true
security.protectionspopup.recordEventTelemetry undefined true
security.remote_settings.crlite_filters.bucket undefined security-state
security.remote_settings.crlite_filters.checked undefined 0
security.remote_settings.crlite_filters.collection undefined cert-revocations
security.remote_settings.crlite_filters.enabled undefined false
security.remote_settings.crlite_filters.signer undefined onecrl.content-signature.mozilla.org
security.secure_connection_icon_color_gray undefined true
security.tls.enable_delegated_credentials undefined false
services.common.log.logger.rest.request undefined Debug
services.common.log.logger.rest.response undefined Debug
services.common.log.logger.tokenserverclient undefined Debug
services.sync.prefs.sync.browser.contentblocking.introCount true undefined
services.sync.prefs.sync.privacy.trackingprotection.cryptomining.annotate.enabled true undefined
services.sync.prefs.sync.privacy.trackingprotection.fingerprinting.annotate.enabled true undefined
signon.generation.available false true
signon.generation.enabled false true
signon.management.overrideURI undefined about:logins?filter=%DOMAIN%
signon.management.page.breach-alerts.enabled undefined true
signon.management.page.breachAlertUrl undefined https://monitor.firefox.com/breach-details/
signon.management.page.enabled false true
signon.management.page.faqURL https://lockwise.firefox.com/faq.html undefined
signon.management.page.feedbackURL https://www.surveygizmo.com/s3/5036102/Lockwise-feedback?ver=%VERSION% undefined
signon.management.page.hideMobileFooter undefined false
signon.management.page.mobileAndroidURL undefined https://app.adjust.com/6tteyjo?redirect=https%3A%2F%2Fplay.google.com%2Fstore%2Fapps%2Fdetails%3Fid%3Dmozilla.lockbox&utm_campaign=Desktop&utm_adgroup=InProduct&utm_creative=
signon.management.page.mobileAppleURL undefined https://app.adjust.com/6tteyjo?redirect=https%3A%2F%2Fitunes.apple.com%2Fapp%2Fid1314000270%3Fmt%3D8&utm_campaign=Desktop&utm_adgroup=InProduct&utm_creative=
toolkit.telemetry.enabled false true
toolkit.telemetry.geckoview.batchDurationMS undefined 5000
toolkit.telemetry.geckoview.streaming undefined false
toolkit.telemetry.ipcBatchTimeout undefined 2000
toolkit.telemetry.isGeckoViewMode undefined false
ui.scrolling.negate_wheel_scroll undefined false
urlclassifier.disallow_completions goog-downloadwhite-digest256,base-track-digest256,mozstd-trackwhite-digest256,content-track-digest256,mozplugin-block-digest256,mozplugin2-block-digest256,block-flash-digest256,except-flash-digest256,allow-flashallow-digest256,except-flashallow-digest256,block-flashsubdoc-digest256,except-flashsubdoc-digest256,goog-passwordwhite-proto,ads-track-digest256,social-track-digest256,analytics-track-digest256,base-fingerprinting-track-digest256,content-fingerprinting-track-digest256,base-cryptomining-track-digest256,content-cryptomining-track-digest256,fanboyannoyance-ads-digest256,fanboysocial-ads-digest256,easylist-ads-digest256,easyprivacy-ads-digest256,adguard-ads-digest256 goog-downloadwhite-digest256,base-track-digest256,mozstd-trackwhite-digest256,content-track-digest256,mozplugin-block-digest256,mozplugin2-block-digest256,block-flash-digest256,except-flash-digest256,allow-flashallow-digest256,except-flashallow-digest256,block-flashsubdoc-digest256,except-flashsubdoc-digest256,goog-passwordwhite-proto,ads-track-digest256,social-track-digest256,analytics-track-digest256,base-fingerprinting-track-digest256,content-fingerprinting-track-digest256,base-cryptomining-track-digest256,content-cryptomining-track-digest256,fanboyannoyance-ads-digest256,fanboysocial-ads-digest256,easylist-ads-digest256,easyprivacy-ads-digest256,adguard-ads-digest256,social-tracking-protection-digest256,social-tracking-protection-facebook-digest256,social-tracking-protection-linkedin-digest256,social-tracking-protection-twitter-digest256
urlclassifier.features.cryptomining.annotate.blacklistTables undefined base-cryptomining-track-digest256
urlclassifier.features.cryptomining.annotate.whitelistTables undefined mozstd-trackwhite-digest256
urlclassifier.features.fingerprinting.annotate.blacklistTables undefined base-fingerprinting-track-digest256
urlclassifier.features.fingerprinting.annotate.whitelistTables undefined mozstd-trackwhite-digest256
urlclassifier.features.socialtracking.annotate.blacklistTables undefined social-tracking-protection-digest256,social-tracking-protection-facebook-digest256,social-tracking-protection-linkedin-digest256,social-tracking-protection-twitter-digest256
urlclassifier.features.socialtracking.annotate.whitelistTables undefined mozstd-trackwhite-digest256
urlclassifier.features.socialtracking.blacklistTables undefined social-tracking-protection-digest256,social-tracking-protection-facebook-digest256,social-tracking-protection-linkedin-digest256,social-tracking-protection-twitter-digest256
urlclassifier.features.socialtracking.whitelistTables undefined mozstd-trackwhite-digest256
widget.disable-native-theme undefined false