Question about physiology and stretching


I have a question about stretching and veins.


"Do you think a vein can be stretched ?”

I have a big vein on the left side along my penis. This vein is a kind of barometer about my erection. If it’s swollen my erection is maximum. After a stretching (basic Up Down Left Right included in newbie routine) with flaccid length the vein is not so visible. I have the feeling an erection can be started..
Then I ask me a second question:

“Will stretching give me a new form of vein ?” for example if I use an ADS.
I would be worried about this considering the fact that my erections would certainly be weaker.