Ammo finicky, poor customer support from advantage arms. - Advantage Arms Glock 19-23 MOD-CA Conversion Caliber

I purchased 2 Advantage Arms (AA) conversion kits, an original years ago and recently an MOD kit for the “optics ready” capability. I bought the AA MOD kit because it's the only optics ready Glock training option I could find or I probably would not have purchased a second kit due to poor reliability. My older kit has many thousands of rounds through it; my new one has about 300 so far. Both are ammo finicky, even with expensive minimags reliability is just ok, but when it's dirty, reliability is really bad! My only purpose for these kits is a glock trainer, so the consistent failure to fire or feed issues provides more than enough tap and rack practice; I don't recommend AA kits for a fun plinker; pistols like the M&P 22 compact is crazy reliable with cheap ammo. HERE'S THE BIG PROBLEM: My customer service experience with AA was unacceptable. The MOD kit is not optics ready, it needs an MOS plate that isn't included. The kit doesn't include extra mounting screws and doesn't tell you the screw thread size on the slide. When I emailed AA I for the thread size I made the mistake of writing, “for the cost of an entire pistol, you'd think a plate, extra screws, and directions would be included,” the reply I got was rude, mocking me about knowing the price, and they refused to tell me the thread size. I can't imagine what it would be like getting help with warranty work. I will never purchase another AA product; I expect a company to provide some basic customer service. I've needed real help (repair work) with a Ruger and Smith & Wesson pistols in the past, both had amazing customer service.