hmmm...
Being it a Visustella plugin makes things a bit more complicated, since their code is obfuscated (and I can't look into it to adapt mine for a perfect compatibility).
However, looking at their plugin instructions, I think I may be able to do something so that checking their code would not be necessary (which may probably work for other plugins providing this same class change feature). Since it is a paid plugin though, I'm unable to run proper testings at this time.
But tell me something... when you try to use CharacterPoses with Visustella's plugin, what happens?
It changes spritesheets successfully (just not taking into account the class change)? Or does Visustella's plugin prevent poses from working entirely?
If the spritesheets are swaped when a pose is triggered, I may be able to add some keywords to make them compatible (so that you can work with class changes). On the other hand, if the answer to the last question is true, than there's little I can do alone =/