Yeah, I have my microSD set to btrfs format, but it breaks auto mount every SteamOS update. I know there are ways to set it to automatically fix this, but I’ve been using a lazier option of just having a shell script to fix the fstab (file that tells the computer what to mount and where) that I run once after every steamOS update.

It’s not a perfect solution, but it makes fixing it easy enough that I haven’t looked into a permanent fix.