Really good plugin, i use it all the time for my testing server, killing mobs quickly and such things. The developer is an really cool guy, provides support immediately for his plugins and tries so hard to fix the problem that has been reported.
I really like this plugin, although it would be nice if you fixed the crashing (Ik you mentioned, but still). Doing things like /magicitems enchants would just bring up the usage, I had to use tabcomplete to know what the subarguments were. The main thing that I think was holding this plugin back was that the commands weren't the easy to understand or use. Another thing you could add could be making it so that the nbt held the uuid of the owner, and the would get wiped from existence if another player had it in their inv, a container in their inv, or it was in any container in the wild.