Potentialy dumb question here, is there any benefit to using btrfs on a non system disk? I'm fairly ignorant on file systems, asfaik btrfs largest benefit is snapshotting, not sure of anyothers.
It certainly is very useful there as well. Depending on the kind of system you have and how you use it, this feature may be absolutely crucial or simply nice to have. If you like to tinker a lot, it’s probably crucial.