okay, before i go insane, can you tell me if Tracktion actually supports setting this flag?
i presume it doesn’t, as my plug isn’t recognising it. if not, is it possible that it can in the future?
cheers 
…no, I don’t think it does, and it also doesn’t support the smpte timecode frame rate flag, as I just noticed.
I can add support for those in the future, but I guess there’s still going to be plenty of old copies around so you’ll need to make your plugins cope with them too.