Hopefully my small insight will help some. A ways back I tried clamping while rock hard as tightly as possible. Of course I got expansion; however, I had a lot of negative PIs. I stopped clamping for a while and went back to it. Now I approach it similarly to drilla. I get a good erection, clamp, kegel to hard, and use moderate clamping force instead of clamping down extremely hard. My PIs since using this method have been great. I’ve only been back in the game for about 2 weeks and expand at minimum 1/4” and I only clamp for 10min sessions.