There actually was a birthday party shop in my area a few years ago. I never did it since it was a place for kids and mine were too old. Don't know of any now but it is possible.
I did a birthday party shop for my son and I’m in south Florida. It was at a trampoline place and was fully reimbursed plus I got an extra payment. The report was super easy too.
I've seen a party shop at a trampoline place on isecretshop. Never heard of the MSC, but they are posted every month and seems like they have trouble filing them.