I've been working on PE2 for quite a while now and I think I have a good ROM on the movements. I'm taking it very easy during the sessions and I go though them feeling comfortable, not pushing myself. But doing the cossacks and twisting squats has now left me with pain around the knee, mostly on the outside. It's so bad that I can't even do a simple squat without feeling it, and working on PE2 is out of the question at the moment.
Joshua, you mentioned here: https://www.gymnasticbodies.com/forum/topic/11805-joint-pain-relief/ that you did some inside squats and it relieved you of your pain. Did you go through PE1 and PE2 with knee pain and then come to the inside squats or did you incorporate them earlier to balance things?