The manual states "Height is restricted to 16 ft (5 m) when the GPS signal is weak and Infrared Sensing System is enabled".
I am not sure what would happen if you taped over the infra red emitter but if you tape over the optical sensors and have no GPS then the drone goes, I think, into true ATTI mode with no position holding capablility and you may crash unless you are already experienced in that sort of flying.
Those optical sensors need fairly good light so.....be careful