Correction: it's not atmos or "complexity index"
Any 7.1.ec3 copy by ffmpeg shows 6 channel
1536kb/s or 1664 kb/s 7.1.ec3 won't play on Apple.
768kb/s 7.1.ec3 plays fine.
1536kb/s 5.1.ec3 plays fine.
No idea what's going on here.
Also @RESET_9999 do you think an eac3 with core inside it can be added to mp4?