if the cooler never gets ran then there will be no problem

If there is coolant running through the cooler the possibility of a problem remains. Not to mention the engine doesn't stop pumping exhaust through the cooler, the inop valve just keeps the exhaust gasses out of the intake stream.

The cooler won't flow exhaust with the plug undone unless the oring goes, I had my egr just unplugged almost from day one, then I did a delete after 250k, the inside of the cooler looked almost new with no build up what so ever.