First, let's be clear. No player is getting fair value for their NIL. They are all being grossly overpaid for it.That would be pay to play…..
Second, contracts have time frames attached to them. So a contract could extend either through the end of the season or through a bowl game. It could run to November 30 with a right for the payee to extend beyond November 30 at their option.
These rules have been totally evaded and there is absolutely a way to evade them to get money to players who perform in bowl games. Whether it's advisable for teams/alums to go that route is another question.