When I was in technical training in the Air Force almost 45 years ago, the Electronic warfare guys were going to school in their own building placed in a part of the Base away from everyone else. It was closest to the building where we went to driver training so when we were given a break we watched them go on brake on their cover free pad with a little envy and awe. Of course we learned of EC and ECC in our classes but no details other than some historical tricks from WWII. We always heard that the IDF took our shared info and made them better in the same way we did with the British.
Amir Tsarfati has reported that they change the systems inside the planes when they buy them from us.