Would having a Genre savvy villain set the bomb to blow on 5 seconds (aka 2 dice) be a real jerk move???
Hah!
Well, he doesn't know how many turns it'll take to deplete down to 2 dice. It might be 5 seconds, it might be 20 minutes! So his genre-savviness doesn't help him much!
Though I suppose you could look at it like the villain knows, but the GM and the players don't.