The https://collector.openwebdocs.org/ project (v10.20.4) found new features shipping in Firefox 154 beta which was released yesterday. Currently, the collector covers about 90% of BCD, so the following list might not be exhaustive. Also, if a feature is in Firefox Nightly only, it is not considered here.

With this PR, BCD considers the following features as shipping in Firefox 154 (bold features are new keys in BCD).

• api.RTCDtlsTransport.error_event
• api.RTCIceCandidatePair
• api.RTCIceCandidatePair.local
• api.RTCIceCandidatePair.remote
• api.RTCIceTransport.getSelectedCandidatePair
• api.RTCIceTransport.selectedcandidatepairchange_event
• css.properties.text-box-edge
• css.properties.text-box-edge.alphabetic
• css.properties.text-box-edge.auto
• css.properties.text-box-edge.cap
• css.properties.text-box-edge.ex
• css.properties.text-box-edge.ideographic
• css.properties.text-box-edge.ideographic-ink
• css.properties.text-box-edge.text
• css.properties.text-box-trim
• css.properties.text-box-trim.none
• css.properties.text-box-trim.trim-both
• css.properties.text-box-trim.trim-end
• css.properties.text-box-trim.trim-start
• css.properties.text-box
• css.properties.text-box.alphabetic
• css.properties.text-box.auto
• css.properties.text-box.cap
• css.properties.text-box.ex
• css.properties.text-box.ideographic
• css.properties.text-box.ideographic-ink
• css.properties.text-box.none
• css.properties.text-box.normal
• css.properties.text-box.text
• css.properties.text-box.trim-both
• css.properties.text-box.trim-end
• css.properties.text-box.trim-start
• css.types.sibling-count
• css.types.sibling-index
• javascript.builtins.Iterator.chunks
• javascript.builtins.Iterator.includes
• javascript.builtins.Iterator.join
• javascript.builtins.Iterator.windows

Updated in other PRs:

• webdriver.bidi.browsingContext.domContentLoaded_event.userContext_parameter
• webdriver.bidi.browsingContext.downloadEnd_event.download_parameter
• webdriver.bidi.browsingContext.downloadEnd_event.userContext_parameter
• webdriver.bidi.browsingContext.downloadWillBegin_event.download_parameter
• webdriver.bidi.browsingContext.downloadWillBegin_event.userContext_parameter
• webdriver.bidi.browsingContext.fragmentNavigated_event.userContext_parameter
• webdriver.bidi.browsingContext.historyUpdated_event.userContext_parameter
• webdriver.bidi.browsingContext.load_event.userContext_parameter
• webdriver.bidi.browsingContext.navigationCommitted_event.userContext_parameter
• webdriver.bidi.browsingContext.navigationFailed_event.userContext_parameter
• webdriver.bidi.browsingContext.navigationStarted_event.userContext_parameter
• webdriver.bidi.browsingContext.startScreencast
• webdriver.bidi.browsingContext.startScreencast.context_parameter
• webdriver.bidi.browsingContext.startScreencast.mimeType_parameter
• webdriver.bidi.browsingContext.startScreencast.video_parameter
• webdriver.bidi.browsingContext.stopScreencast
• webdriver.bidi.browsingContext.stopScreencast.screencast_parameter
• webdriver.bidi.browsingContext.userPromptClosed_event.userContext_parameter
• webdriver.bidi.browsingContext.userPromptOpened_event.userContext_parameter
• webdriver.bidi.input.fileDialogOpened_event.userContext_parameter
• webdriver.bidi.network.authRequired_event.userContext_parameter
• webdriver.bidi.network.beforeRequestSent_event.userContext_parameter
• webdriver.bidi.network.fetchError_event.userContext_parameter
• webdriver.bidi.network.responseCompleted_event.userContext_parameter
• webdriver.bidi.network.responseStarted_event.userContext_parameter
• webdriver.bidi.script.realmCreated_event.userContext_parameter

For more Firefox 154 info, see also mdn/mdn#850 and https://www.firefox.com/en-US/firefox/154.0beta/releasenotes/