Problem with this is there's no specific rule that says mentors need to know that specific content. Maybe they prefer to FATE grind for some bizarre reason. Maybe they just like to flip the market. Or explore or collect. All of this ignoring (or accounting for) the crafter/gatherer/pvp mentors. There's not even a rule that says mentors must have a keyboard to communicate any of those things.

Due to so many variables, attaching any sort of reward was always going to cause problems. No reward, and you get players that want to be part of the system (or at worst just want a fancy crown or possibly the exp bonus).