After what we saw from FFH, taking advantage of Mysterio to create some incredibly trippy (practical and screen-based) dark ride elements/effects was a huge HUGE missed opportunity.
Imagine having your ride vehicle enter what seems to be a mirror maze with multiple Mysterios appearing behind the mirrors (two-way mirror effect), and then suddenly you're in an infinity mirror room surrounded by thousands of Mysterios.
Correct me if I'm wrong, but I remember them saying that the theme park universe exists in its own universe, back when Mission Breakout was a whole big thing. I'm not sure, though.
I don't think the general audience would question it though.