This was kind of a goofy fix, though I'd share in case anyone else runs into the same issue

GE-built 24" compact basic gas range, Mod. RGAS300DM2WW Ser. TV916498R Mfg'd Oct. 2023

The complaint was that the oven was intermittently turning itself on and heating without any user input. Before even running the call, I suspected a thermostat issue, but decided not to preorder it based on cost and availability. When I arrived and discussed/confirmed the symptom with the customer, I regretted not having the thermostat with me, because I was convinced I would need one and it kind of seemed like a wasted trip.

Still, just out of curiosity I opened the unit up, and found that the weird compound thermostat (p/n WB24X31918) had come apart. The additional switch that was crimped on the front of the thermostat body had worked loose, allowing the thermostat shaft to be in a non-off position even when the knob was in the off position. Kind of akin to the issue with spark switches detaching from surface burner gas valves and calling for spark with the knob off, but in this case with an oven thermostat it was a hazard more than a nuisance.

I was able to re-stake the crimp fingers in place to get the unit switching off reliably again, and confirmed repeatedly that I had thermostat continuity with the knob calling for heat, and no continuity in the off position.

With the benefit of hindsight, I'm glad I opted to open the unit up (with some difficulty, kind of a silly design), ended up with a FCC and a happy customer, wouldn't have guessed that this would be fixable without replacing anything