Interesting, what do you simmer, gumbo? Slight mash adjustments for BIAB? Curious / thanks!
In my case/process final hop additions and the ability to keep the kettle from boiling over. I've never brewed BIAB but from what I've read, an SSVR on the element could be handy for adjusting mash temps as you have mentioned.
Gumbo? Nope.... Dungeness Crab? Maybe...