UIGEA (Regulation GG) does not require you to monitor anything. It indulges in the fiction that by obtaining customer certifications and providing customer notices you have prohibited the transactions from taking place.
If the fantasy bubble bursts and the customer receives a restricted transaction you are required to block (reject) that transaction.
_________________________
In this world you must be oh so smart or oh so pleasant. Well, for years I was smart. I recommend pleasant.