Just tested zfs-2.0.0rc2 on 10.9: only one of my pools imports and when I run the zpool import -a -f command, I've got a "Segmentation fault: 11" error.
zpool list only shows the one pool that imported correctly.
Note that I've got my usual "sandwich" of pools/hfs partitions on that drive and the only pool that shows up is the first one.
(the drive contains 2HFS+pool+2HFS+pool+HFS+pool, in that order)