How would I address if that were the case?One thing I can assure you, you most likely DID have thermostat problems before your Opti. The engines you were running prior simply weren't smart enough to tell you about it (at least not COLD engine scenarios). Prior to the Optimax triple-nickle electronics, there simply was no "thermostat fault strategy".
So that meant you just ran it until it blew in most cases.
Jerzia: I'm wondering if you don't have sand built up in the recess at the center of the tuner/adapter plate. See a few like that and they were CONSTANTLY getting sand into the thermistor pin, causing binding and improper thermostat operation/closing. Like Leon said- sand will destroy them.