Firefox for Enterprise Support Forum

I am looking for information regarding the support life for settings that are defined in the Preferences (Deprecated) section of the ADMX templates provided in GitHub. There doesn't appear to be a definitive answer as to when these preferences are no longer applicable to a version of Firefox. The term "Deprecated" certainly applies they're on their way to extinction. But only a small handful of preferences have been ported over to non-deprecated template settings (like Auto Update). Is there an expected version of Firefox where all these preferences are meaningless? Or will they be supported indefinitely? "Industry recommendations' from 3rd party security vendors are bloating my policies in the domain space and I can't definitively say they are 'no longer supported as of version xyz' for all these Firefox Preference settings, which happen to be about 80% of the security parameters defined by STIG and/or CIS Workbench.

in our organisation i need several domainnames to be added in network.negotiate-auth.delegation-uris and network.negotiate-auth.trusted-uris, so that sso for some webapplications is working. some are allready in the list. when i make changes to the list, everything is working ok, but when i clos all mozilla windows and restart mozilla, the changes are gone.