So at this point you know what it is, you know how to avoid being scammed, and you are aware that the most optimal way to deal with these people is to just block them and move on.

With all these things known, you can waste their time by pretending to have trouble depositing the check, saying the deposit went through while doing nothing, saying it worked and then playing hard to get with their “overpayment return” (usually they play on good Samaritan/pay it forward kind of guilt, so just pretend to be an asshole), and fucking with them every step of the way.

Atomic Shrimp on YouTube has done a bunch of these, if you’d rather live vicariously rather than expose yourself.