Hey ac eagle
The board has not been replaced. Though it may turn out that it needs to. The literature and several guys on this site have mentioned an exv driver board. I am fairly certain that I do not have one, but I will double check tomorrow. The exv cable is plugged directly into the J7 plug of the microprocessor board.
I should have mentioned much earlier when you brought it up that many of the sensors have been replaced. I know both cooler saturation sensors have been replaced along with the LWT. I also think that the return gas for Circuit B was replaced, but not certain. I am confident that they are reading correctly, but I will not completely rule it out because so many people, including you have seen odd things with the sensors.
I am in Raleigh, North Carolina. How is your summer going in MA, it has been a hot busy one here.