I have done a couple other parts, such as hd22 barrel nuts, Glock mags, 10/22 mags, etc. I did some destructive testing with Glock mags and they held up really well.
I don't do much with parts kits builds, and these little suckers are easy and cheap enough for me to build just as a test. I know what to expect out of them with other materials such as abs, PLA, and pla+. The breech, sear, and hammer are typical failure points for this particular build and get different types of stress.