Best optics ready option for glock training, but terrible customer support from the manufacturer! - Advantage Arms Glock 17-22 MOD-CA Conversion Caliber

Bought a second kit to have an optics equipped Glock trainer. My older model has probably close to 8000 rounds through it. I love the older model but it's ammo finicky, and when dirty, it turns into a single shot. Having said that, this is the only exact match for Glock ergonomics with an optic. I was disappointed you need to purchase a separate plate and they copied the actual MOS style mounting system, wow what a crappy mounting system! No screw info is listed and the manufacturer seemed to want to insult me instead of answer my questions. He was upset because I said for the price, I was surprised it didn't come with a plate or extra screws and instructions. I guess I'm stuck going to the hardware store and trying to match the tiny thread pattern. Really bad customer service on the part of Advantage Arms; I hope I don't need warranty work!