School locks for inhabited rooms can be opened from the outside with a key.   If they can't, then they aren't code.
https://www.campussafetymagazine.com/safety/classroom-barricade-devices/  
LoOk, folks, my qualifications are psychology and IT, not fire safety, so if anyone can provide a counter-source showing that temp wedges are within regs, have at it with my blessing, I don't have a dog in this race.