Indeed! ZFS support? · Issue #111 · nix-community/nixos-apple-silicon · GitHub
However, I ran Asahi on ZFS root on this machine for a year or so and was overall quite pleased. I wiped the machine several months ago for unrelated reasons and am going back through the Asahi install process.
(Unrelated, but I’m currently running into Boot failure: stage 2 init script not found - #3 by emarthinsen – the poster in that thread also was on ZFS.)