First up, I love Batocera. It's absolutely awesome. Autoconfiguring controllers literally makes it 10 times easier to use than most of the competition.
Onto the point: I know you guys have probably already considered this before, e.g. https://batocera-linux.xorhub.com/forum/d/1170-number-of-files-limit-on-fat32/4 but I wanted to ask
1) Is it possible to move the main/internal ROMs folder to an ExFAT partition today?
2) Would you guys would consider making that the default behavior?
I understand that ext4 is a legitimately better filesystem, but switching to ExFAT would be a significant usability boost because it would allow users to easily copy over files from Windows and Mac systems rather than having to boot into Batocera and either do a 2-step copy with a spare drive or else figure out networking. (Neither of those things are hard, but just copying the files to the Batocera drive is almost certainly going to be easier for most users.)
In my mind, the biggest drawback of ExFAT is the lack of journaling, but that should be much less of an issue in this case since Batocera would rarely be writing to the ROMs folder. The underlying linux stuff could stay in a ext4 partition and get all of it's benefits.
I suppose it might make more sense to put everything in the SHARE folder into the ExFAT partition, rather than just the ROMs, but it's the same idea either way.