I believe that LOT theory has some merit.
I think what Bigger was trying to describe with his LOT Theory was that there is some length of “inner penis” which is not expressed outside the body because the ligaments are holding it back. This is certainly true, and it is the basis for penis lengthening surgery (cut the ligs and “pull out” the inner penis).
At some angle (i.e., your LOT), the ligs become lax just enough to express the full inner penis length. The more you can lower your LOT (by stretching the ligs), the more inner penis is expressed at lower angles. Eventually, your LOT becomes low enough that further lig stretching stops being productive, because the ligs are no longer holding back your inner penis at any normal anatomical angle.
Somebody with a high LOT can make his penis hang lower and perhaps even get a longer erection simply by stretching the ligs. Somebody with a low LOT cannot do this. Tunica growth is required.
LOT is useful to hangers because it shows them what angles are needed to target the different structures. Although, generally, one should hang at high angles for tunica and low angles for ligs, there are a range of angles in between (such as SO) for which it is not always clear what structure is being targeted. If your LOT is 6, you can be pretty sure that SO will target the tunica; if your LOT is 11, you can be pretty sure it will target your ligs.
Some tunica stretching may occur by hanging at downward angles. However, stretching at downward angles is probably not as productive as stretching at upward angles because the ligs shield the inner penis from receiving the full traction force.
I have often wondered whether most tunica growth actually occurs at the inner penis. Inside the body, the corpora cavernosa split into separate crura. I’ve never seen a clear description of the tunicae surrounding these crura. Are longitudinal fibers even present? If not, or even if the longitudinal fibers are simply less dense than they are in the rest of the penis, then this region would likely be less resistant to stretching than the outer areas.
If this were the case, LOT theory would matter even more, because, when targeting the tunica, you would always want to stretch above your LOT to apply traction to this region.