Thanks for the write up! Only thing I will add is my personal experience.
Kel-Tec PF9 is garbage after about 250 rounds IMO.
Bought one as my EDC when off duty. I'm local to Kel Tec, and wanted to support a local company. Good price, seems like a good decent EDC gun.
Started shooting it regularly. About 250 rounds in, started to get FTE's. Thought it was just dirty. Ok, no problem, made sure to clean the gun very well.
Took it the next time to the range. Same issue, but became more frequent. 1/15 would FTE. It got worse as I shot more. At one point, it was 1/5 FTE.
Took it to Kel Tec (again, local to them) GREAT customer service. Walk in, gave them the weapon, and left an hour later with a repair at no cost.
Went to test it. New problem. FTF issue. Again, started off every 1/15-20, then got more frequent. Took it back again, fixed again.
About a week later, took it out again. (At this point, I'm almost tired of shooting this *&^^##& gun, and carry something else I can rely on)
Shot good for about 120 rounds, then failed again to eject.
That was the last time I shot the weapon. Cleaned it really good, then traded it in at the local gun store.
Also, this isn't a new issue. They've known about this issue for quite some time, and for some reason, don't re-engineer the thing to fix whatever the issue is. This tells me they don't care about their product, or it's reliability, only the money.
JMHO of course!!