At this point, Manning's lucrative NIL deal is based on his namesake as he has done nothing to separate himself from that. You would have to look at the details of his contract, but I'm sure that he does promote products and businesses on his social media accounts, does in person promotions and autograph signings, has his face on Austin billboards, and promotes the school and the football program. He is not a prominent national figure, so we will not see him in TV commercials outside of the Austin viewing area.
If the collectives are smart, the contracts are likely short, maybe for a one year terms. If his marketability wains-maybe he gets hurt or doesn't meet expectations on the field-the next deal won't be as lucrative. I will add if he is still riding the bench as a Junior or Senior, his contract will not be worth much. Right now, his current deal is based on the potential success he will have on the field. Like much of investing, there is a level of risk by the investor (NIL collective).