If the attachment points between the shaft and the pubic bone are secure enough to decide the length of the exposed penis, then how does the extra inch show up past the exit point and between the attachment point on the shaft and the end of the penis?
Your Comparison.jpg (rootsnatty) shows a lengthened suspensory that is roughly an inch longer, so it hangs an inch lower but somehow you’ve drawn it connecting an inch further into the body, exposing more penis as a result. It seems like the attachment to the shaft moves?
It seems to me that gains in length more likely come from tissues increasing between the attachment point (that doesn’t move) and the end of the penis. I am no doctor, and can’t quote studies to back anything up. I am basing this opinion on my limited understanding of anatomy as well as my own experience in gaining about 1.75” in length from of extending exclusively straight out, which has shown no change in exit point, no change in erection angle and no sign of exposed ligs.
Also, I have always seemed to point to the left (pre-pe) not a curve but exit pointing at a slight angle to the left (true north instead of magnetic north ;) ). My understanding is that is likely caused by ligs on the left side being shorter than the right. I would have expected, if the ligs were being changed attributed to growth, for them to have equaled out by now, but I still point slightly left.
You are correct that I didn’t draw the lig attachment in exactly the same place. I should have measured to get that part right. But the lig attachment place isn’t the issue, as the lig lengthens, this point will move closer and closer to the surface of the body. In some anatomies like neverenough9’s, the lig gets so close to the surface that it actually protrudes and looks like, as he accurately describes it, “an upside down turkey neck.” This, however, is uncommon as the suspensory ligament proper is very deep inside the pelvic cavity. The two ligaments you sometimes see protruding in pornstars on the sides of the penis are actually one ligament, the fundiform ligament, which is much closer to the surface.
The reason you have had the experience you have had is that you have mostly extended straight out, focusing the stretch force on the tunica, not an ideal angle to produce lig lengthening.
Don’t get me wrong you can gain both ways, but my point is that lig lengthening will produce results as well as tunica lengthening.
Maybe I should make a 3D model to better illustrate this?