The current setup is not multithreaded in the relevant ways. So the real decision point was whether to take an existing large C++ codebase and try to safely ma

The current setup is not multithreaded in the relevant ways. So the real decision point was whether to take an existing large C++ codebase and try to safely make it multithreaded or to take that same existing codebase, run it in separate processes, and make the communication work. The latter is actually a simpler engineering task, in my opinion, and paves the way for doing things like sandboxing and whatnot once the initial rollout is complete.