analog said:

Ok. I thought the limitation was "non video datastream" *while playing back* but perhaps it counts all sub tracks in total?

All audio tracks and subtitles are included simultaneously in the limit, not just the ones playing. Audio is pretty easy to calculate since it tends to be CBR, but subtitle bitrates spike when subtitles appear onscreen, and they spike higher for bigger subtitles. It's kindof a mess to figure out any way but just doing it. I think Harmy tends to only include the 3 original audio tracks in lossless form, so we may be fine. I just wanted to mention--there's a limit, and it's possible to hit it.