Yeah pg only shotguns also generally suck, my dad has a .410 Mossberg like that and it is ok to shoot.
I also have such a KelTec SU16,too bad we can't have the real folding stock version in CA.
Also yes some of them are poorly designed, IIRC on the Daewoo rifle so equiped, the magazine release is blocked when the stick is folded.
I think the main good thing they have going for them is compact storage in places like a briefcase, motorcycle, ect. Stock should be extended for any serious shooting of course.