Currently Mannequin cannot export layered PSD files, or even PNG files of the different depths that comprise a character, right?

I think I already know the answer to this question, but I need to make sure before investing the hours of work that wouldn't be necessary in case I am mistaken...

Yes, the feature is not finished yet, and the button that are available in the nightly builds is just a placeholder for now.

Thanks for the response time !
Keep up the great work.
You've got a lot of fans ~