I disagree with this point and this is why…
I usually pump around 5hg for about 20-30 minutes. I usually throw in a couple of high pressure “sets” (8hg-12hg) during the middle and end of my routine. My goal is to push the tissue to stretch to new limits and keep it there briefly. During these high pressure bursts I will kegel in blood between pumps. I will pump, kegel, pump, kegel, etc. Each time I force more blood in I get immediate expansion. I observe my penis increase in length from about 1/8” to 1/4” for each pump until it maxes out and I can’t tolerate any more pressure. This tells me that the increased length is due to increased blood volume pressing on the tunica, not fluid build up. There is no way edema fluid could build up that fast under the skin. I also know it’s blood because when I let the pressure off the length retracts proportionately. I have had good success with this and am reaching greater lengths in the tube than previously. I haven’t had problems with dough-nuts or excessive fluid.
I think pumping is very effective at stretching the tunica.
Thanks for your explanation on this, Iguana, and if it works for you, good for you. However, I must add the mandatory disclaimer that such vacuum levels and routines are not for newbies, and that more experienced pumpers should proceed with caution.