Best they can do is limit the portal activity, Limit the transfer portal window to May/June when Bowls and playoffs are not in play. Give it a good full two months open for visits-etc. Also allowed one free transfer but next transfer you must sit a year. A third transfer is only available for graduate students. As far as NIL, they can't do much.
Unless a conference steps in like the Big Ten and says they are splitting the pot with players, like for example taking 25 percent of the money from schools pot. Paying the players a base for being scholarship and also pay those who play percentage. Schools don't want these players to be considered employees because of legal concerns, but there is nothing stopping the conference from considering them employees of the Conference.
Hypothetical 25 Percent of Each Schools TV contract is 25 Million Per School. 10 Million goes to the base salary of each scholarship athlete. (117k Per Person Per Year (85 Scholarships)) 15 Million is a bonus for those who actually hit the field.
Based on a 13 game season. That leaves 1.15 Million available per game to be earned on the field. Depending on play percentage per athlete each game. This is the draw for Walk ons to get paid but are not on scholarship. A average college football game has 160 plays per game. If someone is talented enough to play both ways on offense and defense, they will get a full percentage. (Plays played in a game)Divided by (Total Plays) Multiply by 1/11 of 1.15 Million Available that game = Gameday Payday.
A player playing both ways on offense and defense, Lets say they play 130 plays out of 160 is 81.2 Percent of plays on the field. He would take home a Gameday Payday around 85k for that one game.
This would truly pay for NIL because of their TV exposure. Opt outs in Bowl games would stop, players would try to get on the field more than ever before, you would not have a situation similar to these High Profile athletes who get "injured" when a season isn't going well with plans on transferring out at the end.
Just a Hypothetical, one can dream but this is the best idea I could come up with. Hopefully someone has a better one considering the circumstances we live in. Some of you will say it will take too much away from the athletic budgets of these schools. Will not split the pot enough to other sports, TBH what other sports bring in as much money as football? Another thing about this I would love, it would get guys who are so uber talented to start playing both ways. Who wouldn't want Cooper for Iowa playing both ways?