Flexibility aside, Mahomes is taking it up the ass with all these huge cap raises. QB prices in the next years are going to get stupid and he has an AAV in the 40's locked for a decade. I don't know what happens when the guaranteed cash is up, but I'd imagine he'd love to get a cut of these massive cap raises.
For that matter, anyone who decided to lock up a player long term made a great decision cause those prices should only be going up. Sucks to be the Bengals who have had their thumbs up their asses with Chase and Higgins.