I don't have a local to Boulder suggestion, but I have a shop in Parker, that actually took my fridge out so they could get to the Starcool evaporator in the back of my van. I gave them a hand made diagram of how the system was all connected and they found a leaking hose connection on the rear evaporator and fixed it. They have also found other leaking connections in the whole AC system and replaced those hoses too.
The shop is Parker Automotive
https://parkerautomotiveinc.com/contactus
I know they are not close, but a shop that is willing to remove RV components to get at and fix an issue, now that is a shop I will take my van to every time!!