Bluefin and Aurora stable/GTS both have zfs.
Bazzite is a bit trickier. We currently don’t build the zfs kmod for the fsync kernels (and we are removing the fsync-coreos-stable possibly which had zfs kmods building).
That said doing something like the fsync-coreos-stable in akmods in your repo to build the zfs kmod and sign with your own MOK would work.