I have several red dot sights including Aimpoints and Fastfire that I have tried on multiple handguns. I am constantly searching for the dot when it is mounted at the rear of the slide with no visual boreline reference available. Take the front and rear sights off of that Glock and see how fast it is without the sights for a reference to find the dot. It might not fit a conventional holster but I bet RL could make somthin up that would work Compitetion race holsters are little more than a couple of pieces of plastic and metal rods holding a pistol with big comps, and mounts with big dot sights.