Who are you protecting data access from in those cases? My suggestion was that it's probably more practical to run those kinds of solutions on a hardware stack you trust; in our basement or in a small box on the wall in your living room.
Besides, the specific extension we're talking about protect registers and computation and not shared memory.
Issue is, unless you can be 100% sure you hardware has not been built with a vulnerability or backdoor, or subject to an evil maid attack....then you can't be sure its trustworthy.
