I only arrived at that conclusion because I only started smelling it after my AC quit. At first I didn’t know what the smell was and I didn’t realize the clutch was shot. After finding out it was bad on a warm day I thought maybe it was the burnt clutch coil itself I was smelling. But it is now disconnected and I keep smelling it. We’ll see if it goes away after I replace the clutch. To your point, drying the carpet could help prevent mildew so maybe you’re right.I think it’s just to dehumidify from wet carpets from snow in heat mode.
I used to run mine in floor/vent which doesn’t run the compressor (I think), and yeah you could smell the hot plastic when the motor finally got nice and toasty.