So I got this to work with the major bosses; well at least using master's version. However it does not seem to be working with minions of seeman (bottles still protrude out the rear) and on seeldier it does not work. Basically the co-op bosses and the clones if created still come out with their weapons showing mid way in their bodies.
I'm guessing you need to update another plug-in to fix the issue somewhere. By the way thanks master, it does work like a charm; my OCD was starting kick in every time I witnessed this issue in game. Probably need to do some more research to get this fix on the other issues. I know I am missing something somewhere. Just have no idea where to start.