Aye, keys aren't duplicated when you duplicate a bone. The tricky part on my end is mostly just managing all the data when a bone/attachment/slot/etc is duplicated, and also how to prompt the user in the UI. Soeren and I discussed this before and I think we figured that it wasn't too useful, but I think the use case we considered was different. It seems useful for effects needed in multiple places. Task:
https://trello.com/c/2z9SvE5x/118-copy- ... e-slot-etc
Here's an idea, you could use the unreleased skeleton attachment. Eg, here are two spineboys attached to the goblin's hands:
http://i.imgur.com/azLI2U2.gif
Eh, the export didn't compute the image bounds correctly and the spineboys should be playing the walk animation... but the idea would be your effect is a separate skeleton you an attach as many times as you want. It'll be some time before I have a chance to polish the feature though.
