If you always played with the same name set after set then enforcing this policy makes sense. Because going forward people will learn. If you are using different names set after set, you will be teaching this lesson (throwing away your sets) of yours pretty often in my opinion if it is indeed true that you message the people you hit telling them you have a 72 hour retal policy. .

Friends will learn not to ally you because, "Yeah, come mid set, Bobby is going to be wasting my turrets yet again (though they can make up for this by dropping you and hitting you immediately after)". Others will decide to test out this policy of yours regularly just because.