I have my doubts that MediaInfo and FFMpeg will ever come to a convergence in this respect. And in 2025 nobody except a few geezers like you and me will even know that the DVD format ever existed...
But I do agree with your conclusion. It is hardly worth the trouble to make A2D foolproof for handling source videos with 8-ch audio, especially for ATMOS. Experienced users have a choice of several workarounds.
But still I have a hard time conceiling the fact that I am a perfectionist. It bugs me that software like DVDStyler which is completely FFMpeg based can handle such sources without problems, and AVStoDVD cannot...
This issue would not exist if DirectShowSource had a way to specify a specific audio track for decoding (like FFMS2 and LSMASH have). Probably this won't happen anytime soon.
Cheers
manolito