About the original question, over time on hrt you do lose size. I've been on hrt for nearly 20 years and have lost some tissue. Thankfully I had more than enough to start 😒with, so the loss shouldn't be troubling to my surgeon. I think if you don't exercise it once in a while, the nerves begin to fail, and when you get srs in this scenario you will still be unable to orgasm.
Echo is right that Suporn and Chettawhut do tend to get better depth on average. BITD the penile inversion surgeons typically got 5 while Suporn was getring 7. Originally that was the big draw for Suporn-his consistantly higher depth attracted clients more that the aesthetics at first. I think the PI surgeons may now be getting close to 6; but Suporn and Chet still at 7 or more. (Ironically Sanguan who uses a very similar method to Suporn only gets 5, but then again, the last I heard was a few years back). There are trade offs with either approach.