I'm glad to see open-zfs.org for exactly the reasons you mention.

I've been runnning MacZFS for years, but it's currently way behind at zpool version 8, zfs version 2. At one point I put a FreeBSD machine in the basement, with plans to stream snapshot diffs for backup, but the version mismatches prevented me from doing this in a smart (zfs-based, rather than rsync-based) way.

Looks like this central coordination point ought to help the porting of features/versions from the Linux branch to the Mac branch.