Doubles- you might want to hop over to this thread and read it if you haven’t. CLAMPING Everything You Ever Wanted To Know
As far as your questions- Dorsal nerver bundle runs on the top of your penis.
look at this diagram
penis%20anatomy.jpg
You can damage those nerves doing it that way and if I understand right- you damage nerves nough times and they will not repair so you will lose feeling. the top of your penis especially right behind the glans has a lot of nerves.
I actually noticed that after clamping with the "A" method it was much easier to pee immediately following clamping almost as if the "B" method was crushing the urethra.
Like you I was doing the "B" method. I have switched to the "A" method and after doing it a number of times it feels like I am getting almost as rock hard. Either way- better to have to do more clamping and see slightly slower results than it is to lose feeling in your penis.
I think the keys are to use a good underwrap- BG likes a cut up mousepad or wrist wrap. I prefer really good pipe insulation as it’s much softer than the wrap or the pad, only drawback is you have to throw away the piece you are using about every oher week as it will start to shred, but it’s cheap enough it shouldn’t matter.