This seems like an awful lot of work. Is Plat really worth that much to you? You'll get the same point bonus as you get as a Gold and Plats don't get extra award access ( a la Hilton Diamonds). I went from Gold to Plat last year and it's nice but not THAT nice. I get nice rooms, but rarely suites. I get free gym access, but many properties still don't charge for their gyms.

My guess is that you can do these "mattress runs." I seem to recall a thread from a while ago that said that there is a technical rule against flipping from one property to another within the same area, but that it's rarely enforced, largely because it's tough to determine how far is far enough to rationalize moving, properties are usually separately owned, etc. But I think you should consider whether it's really worth it.