Here's my poor-man's RIMS. I just watch the temp on my mash-tun and run it manually. Man a PID controller'd be nice.
From Left to right, Boilermaker 20 gallon boil kettle & CampChef 60K burner, MoreBeer HD 15-gallon mash tun w/Autosparge & CampChef 30K burner, March Pump mounted in toolbox, MoreBeer 26-gallon HD HLT and CampChef 60 Burner.
I've recently upgraded to a 20-gallon Boilermaker for my mash tun and have added a site glass onto my HLT. The input on top is still an Autosparge with a dial thermometer T'd into it. If I am single-step infusing, then I wrap the kettle in reflectix once the temps stabilize. I just have to pull it off when I heat so I do not melt it (anymore).
The only time I've ever had a potential scorching or over-temp issue has been pre-pump when I did not realize you had to constantly recirculate and intermittently stir.