I'm giving some serious thought to cutting the fan wires. Yeah, I know it's not the best idea in the world, but it's not unreasonable either:
a) This is not an expensive inverter at $100. It's small and light, which is what I was looking for. To keep costs down, it's easy to see the mfr. cost savings in not installing thermostatic control on the fan.
b) The load is only 55w. That's not a lot of work for a 350w inverter.
c) I can mount a small, much quieter 120v fan in the cabinet to dissipate heat from it and the receiver.
Bad idea?