I would love to see this as well: having 96-vCPU Lambda instances (or instances that match the biggest C-family instance you have) would solve a lot of problems for me. The execution model of Lambda (start a runtime, handle requests, AWS handles pool management) feels much easier to use than managing a pool.
Someone from AWS once commented to me that "if you're ever having to manage a pool rather than letting us manage it, that's a gap in our services".
