I recommend stretching in all directions. It’s important to stretch down at least some of the time because the lig fibers actually blend into the top surface of the shaft. Stretching the ligs therefore targets the top surface (dorsal thickening) of the tunica. Stretching up targets the interior parts of your shaft and especially (I think) the ventral thickening of the tunica. I think you need to stretch all of it to see uniform growth.
Hey, maybe that can actually be presented as a hypothesis. Really, this is more along the lines of a wild assed guess, presented as food for thought:
Stretching up targets the ventral thickening; stretching down targets the dorsal thickening. Spending all your time stretching up causes disproportionate growth along the bottom surface of the tunica. Spending all your time stretching down causes disporportionate growth along the top surface of the tunica.
Wouldn’t it be a bitch of that disproportionate growth along the bottom raised LOT, whereas disporportionate growth along the top decreased it? That would actually agree with the predictions of Bib’s LOT Theory, although for a reason different from the one that Bib gave.
If my hypothesis is correct (and I’m not saying it is), all that LOT would tell you is whether you are taking a balanced approach to PE. If your LOT is dropping, perhaps the top is growing faster than the bottom and it’s time to stretch up. If LOT is rising, the situation is reversed and it’s time to stretch down.
I’m seeing a new model here (I hope not a new simulator!), where the penis is represented as two cords. A first cord extends from the pubic symphysis to the glans and represents the dorsal thickening. A second cord extends from the pelvis (ischiopubic ramus) to the glans. The second chord is actually two cords, one for each CC, but we can think of it as one. LOT is then determined, in part, as the ratio of these two lengths (adjusting for offsets).
If there’s any validity to this idea (and I’m not saying there is), then LOT could be useful to gauge progress but would say nothing about one’s potential for gains. A person’s starting LOT, at the beginning of PE, would probably be a useless concept, except as far as it would form a baseline for tracking uniform growth as time goes by.