microb launches fast because it preloaded. IIRC You can unload it with browser switcher app.

And about launch speed. Sadly they seem all bit slow (what is slow?, well to me it´s app that doesn't start in 1-2s to point where you can interact with it) to start. At least currently apps that have been made with python.

I doubt that you gain any speed increase from unloading microb. Best thing probably is to keep those programs running that you want to access fast.