It's ashame to have a nice beautiful system and have to use a bunch of crappy insulation. Take that stuff off and keep experimenting until you dial it in naked.
Mash in and let the grain hydrate for 10-15 minutes. Then start the flow and build up to full flow over another 10 or so minutes. You can use minimal heat if you're low on your strike temp. Once you have full flow through you RIMS tube denaturing the mash is a low risk. I'm not saying apply full power, but plan to move you mash temp no more than 1 degree over about 2-3 minutes. Take your time on temp changes, but there is no reason you can't manage the offset on your system to hit and run at your desire temp. It going to take a few iteration. Let that system shine.
