Wake up! Time to fly!
300 ft for LOS is really not very high. I was at the field a few weeks ago flying FPV with Baro and GPS elevation on my OSD. I was cruising around at 300' thinking I would be above the gasser flying at the field, only to be suddenly awaken by a gasser missing my nose by about 10 feet going right to left. :-O From the ground, he really didn't look that far up. This was only a .45 plane, so nothing extraordinarily big. The whole 400' bubble thing is a joke, even LOS. Height wise(Z) is doable, but 400' around the pilot (X/Y) really isn't much. I can't even use the whole field we have been flying at that close range.
Im on our side NOT the gubbments