Of course, a question would be...
If you mounted the M80s vertially with 2 (or more) FMBs, would it improve things at all? You'd still have the center of gravity far away from the wall, but it could be supported by at least 2 different things..

Actually, all in all, I don't think the FMBs are suited to this project except for the VP150.

I am the Doctor, and THIS... is my SPOON!