Please stop using send/recv . Your backups should be based on non ZFS tech to avoid all your eggs in one basket. Yes send/recv is fine for immediate recovery, but other than block level replication for immediate (my server is now inside the tornado) recovery this isn't advised.

Also, who cares if a single filesystem dies, that's why you have inter-server replication. Nuke the bad server and rebuild before the next 3 or 4 die.