I figure I have a better chance of configuring Linux for my accessibility needs.
Especially Linux Mint. But there's no compatible version of Linux Mint, so I tried Ubuntu, and settled for Fedora.
https://wiki.t2linux.org/distributions/overview/
I tried using hfs+ for the shared partition, and then ntfs, but even if both systems could read it, only one could write to it. I could use apfs with these drivers, but want to make sure I've got a good Linux setup beforehand:
https://www.paragon-software.com/home/apfs-linux/#