It may work, but that level of aditional complexity is not needed at all for what he needs to do. It is basically using a sedgehammer to pound a nail. VPLS etc. is not a feature offered, nor would you want to run, on EX products.
Single Q-tag will provide he best solution, with easiest and most cost effective implementation, in my view. Anything else is over-kill ands creates unneeded complexity. KISS rule!
Again my 2 cents worth.