One concept I really like is to just identity map the whole address space and run everything with full priviledges. With a sufficiently high level memory safe l

One concept I really like is to just identity map the whole address space and run everything with full priviledges. With a sufficiently high level memory safe language with good concurrency and memory regions support, you should be able to statically enforce most of the guarantees that the hardware provides and at the same time get rid of context switches. Untrusted code in a memory unsafe language would simply run in a VM.