Uncle Monster wrote:

... something I read indicates that the heater is for adding heat to the
"control compartment" to fool the thermostat into making the compressor
run for a longer period of time.

Is the heater always on? Maybe it turns off when the compressor runs?
Why heat the control compartment instead of the box?

If the control is heated, the thermostat could still work, but the fridge box
would be colder than without the heater, given the same thermostat setting.

Putting a bulb in the box would just increase the run time without affecting
the box temp.

This could be more efficient with 2 fans and 2 thermostats and no heater.

Disabling the door heater and auto-defrost could also help.

Nick