My penis started to point down - it was visible; I would add that the shape and size of the fulcrum is relevant too.
I quitted doing fulcrum downward stretches, and if I’d do again I’d add upward fulcrum stretches to balance the effect, although these latter will not have a big effect.
I think two things should be kept in mind : first, tunica is thougher on the dorsal side. Many believe this part of their penis is their ‘limiting factor’, but actually this is misleading: you’ll have way more succes elongating the dorsal side that the ventral side of the penis, because the latter is more elastic. I’ve never heard of anyone developing an upward curve; some of those who had big length gains, adversely, either developed a downward curved or straightned an upward curve.
The second one, is that fixing a curve is harder than developing a curve. You have a curve in your penis because there a part of TA it is tougher, stronger; this is from genetic or early development of the body; to correct a curve, you have to make the other side (the weaker) stronger, but, as you can understand, even an indirect force will make the stronger side get stronger faster than the weaker will get stronger (hope it is clear what I mean).
Neverthless, some report being successfull in correcting a curve; an higher number report that they developed a curve with PE - expecially if one pumps with to high pressure and/or a too wide cylinder. All this seems consistent to me.