The system is honestly pretty forgiving on the whole “3rd dimension” on spells that are intended to be “2d” like say Fireball Lvl 1. But I agree that learning to draw the spells (including learning to draw them mostly flat) is an intended part of the learning curve.
Just out of curiosity when you say that it’s impossible to cast Polymorph in a clutch situation, how many hours have you played the class for at this point?