The Persist behavior only preserves stuff if you come back to the same layout. I'm looking for a way to let some items be persistent, but items in my inventory will follow me into a different layout.
As for plugins: I won't have any trouble with discontinued or poorly maintained plugins/behaviors if I am the one writing the plugins ;-B I couldn't find anything to suggest that families are polymorphic with respect to functions, but I just got my item behavior up and running. I have two items, and pushing a key triggers whatever item is in a particular slot, and then each item does it's own thing. It's just a little glue really. This way, at some point down the line I can very easily do crazy stuff like a cursed sword that sets you on fire when you pick it up, or enemies that can be placed in inventory slots.
I'm still having trouble keeping stuff between layouts. I noticed that even though itemslots are global and positioned on a global layer, they get reset every time a new layout starts. What is the best way to fix this?