Crosscheck would require integration with pos. Data used to ban accounts is theoretically stored/analyzed distinctly from live POS transactions, otherwise Bana would happen instantaneously.You would think if they were really smart they could just block it from working in the first place. If the code isn't associated with your account (like in the list of current offers) then it wouldn't work.
That said I don't chance it anymore. I did a few times in the past before I thought about and heard some people have been banned for using someone else's coupons.
But if they could integrate it would be possible to impose trade limits on a live basis instead of using bans. The system would just refuse to complete a trade when certain limits were reached. But this requires TSQL or the like. And as we've heard before their computer systems are old and underpowered.