Great idea. Whether brainstorm mode is actually useful is hard to say without trying it out, but it sounds like an interesting approach. Maybe it would be a good idea to try running a SWE benchmark with it.

Personally, I wouldn't use the personas. Some people like to try out different modes and slash commands and whatnot - but I am quite happy using the defaults and would rather (let it) write more code than tinker with settings or personas.