So basically it’s currently still a cluster****. Unless we can coordinate a summit of project leads and get everyone to agree to a frame standard, it’s likely to continue to be a mess. Sorry. I know how much of a pain it was just finally arriving at NTSC GOUT after all those PAL GOUT battles.
IMO all of the frame standards under discussion make no difference at all for subtitles. Only the two-frame differences are detectable to me for audio, and I’ve even unfortunately seen evidence that this even matters for some dubs (i.e. German). I’m sure there’s someone out there who can detect a one-frame sync difference for audio, but that’s not me.
As for new tracks, hairy_hen made a new 4K83-synced 5.1 track, which doesn’t sync to DeEd. However, I’m sure he’d be willing to make a GOUT-synced track for a new DeEd. And even if he’s not available, I’ve made a GOUT-synced version of his new 5.1 track and it sounds seamless to me (although I would definitely rather get it from h_h!). So it’s pretty easy to take theatrically-synced audio and convert it, if and when new tracks come along.