I have been able to introduce PS well in most ponds when they are stocked in the beginning, but getting them to take in an established pond has been more challenging but not impossible.

My in-laws live on a golf course in southern NC right on the coast just north of Myrtle Beach, SC. The pond in their back yard has CNBG and a healthy population of LMB. The pond also contains a healthy population of PS. I have been fishing that pond for the last 4 years and every time I go I can catch PS, some are over 8". When you net the pond it shows signs of YOY and other age classes. I am sure RES would do well in the pond as well with as far south as it is since CNBG are present.

My grandfather is a member of of a shooting club in central PA that has a fishing pond on the grounds. The pond is full of stunted 8"-12" LMB. It also has plenty of 8"-11" BG and a good number of 6"-8" PS. It's been this way for over 20 years now. That pond is about 2 acres in size and also has YP and BC that do well. Not sure why all the species seem to maintain, but if you don't care about fishing for big bass, it's an excellent panfish pond.

I've personally never seen PS stunt, I am sure they can though. They look a good bit like RES, but are far easier to catch and seem to be more adaptable to changing food sources, able to eat like BG or switch to the hard shelled foods that RES prefer.

They're quite common in the Potomac River by my house. If you run a beach seine there near vegetation in the summer, you can catch 1000's in a single pass. They seem to prefer vegetated areas and don't do well in ponds that are devoid of vegetation. They can be pellet trained, much more easily than RES in my experience. If only they reach a little bigger size, I think they would be a much more commonly stocked pond fish.