With MacZFS, unmounting a filesystem could be a pain, because mds (Spotlight indexer) had files open on it. I had to do the following:
sh-3.2# launchctl unload /System/Library/LaunchDaemons/com.apple.metadata.mds.plist
sh-3.2# zfs umount -a
sh-3.2# launchctl load /System/Library/LaunchDaemons/com.apple.metadata.mds.plist
Does ZEVO CE also have that issue, or does it take care of it somehow?