I guess you will end up with permanent Lymphedema under your penile skin, which will make your penis more liable to infections and such. This means that some of it, if you repeat for longer times will get permanent. Which isn't healthy.
The only benefit i see with this is that your penis will seem bigger visually and if you hold your hands around it. But as soon as you add pressure/compression with your hand or a tight pussy, you should get back to the regular size of your penis, which hides behind
all these fluid buildup. Not fun when the girl sees your penis and "WOW" and then: "What the fuck, it didn't felt that big."
This is how i see it. Everyone talks about that you should go with a maintainence routine when you are at the size you are proud of. I haven't checked this up, but if you MUST have jelqs/stretching or any other unnatural PE technique in your maintainence routine it makes it even more clear that it's mostly about lymphedema under your skin. It's like they want us to maintain the lymphedema until it gets permanent (This only correlates to girth gains)
I think that Edging, regular erections & Keegels should be enough for a maintainence routine. This to not make this "space" between your chambers and tunica, because this will decrease your size. A constant natural pressure against the tunica should be enough.
But if they would say this doesn't work, that you HAVE to have jelqing/stretching/clamping and other things in your routine, it makes it even more clear that they want us to still keep the "lymphedema" beneath the skin.