Coaches can't directly control fans, they can only encourage them to show good sportsmanship.
Coaches do control their players and can have a talk with them before a game letting them know vulgar, disgusting behavior will result in running steps, stairs, loss of playing time and $ fines of their NIL money

for violating their NIL code of conduct. !!!
Either Coach Vigen didn't have that talk with his team or they didn't listen. If I were him, I would use all of the above approach: loss of playing time, stairs, laps, $ NIL fines, and the guilty players would be making an " apology video" apologizing to The University of Montana, it's students and fans, and I would also let the guilty parties know that any repeats will lead to expulsion off my team !!!
And if I were MSU's new president, I would have a heart-to-heart with my AD Leon Costello and tell him if I see any such behavior in the future, he is to monetarily fine the coaches of the football team and a letter of reprimand will also be placed in their files.
I was blessed to know Dr. Mike Malone, MSU's late president and eminent Montana historian. Mike would have been absolutely livid if he had seen any of MSU's players displaying such rude, boorish and vulgar behavior, there would have been hell to pay, and s___t would have started flowing downhill rapidly from the president's office starting with his AD to abolish such behavior ASAP. !!!