Hi Hopeful,
I don't have PN but I have nerve damage and CRPS and generally fussy nerves in one leg.
I can see where yoga has the potential to adversely affect nerves. I have been doing yoga for over a year now and have noticed that it can aggravate nerves if I go into some of the positions too deeply. For example if I downward dog or forward bend so that it looks like a textbook perfect pose then within a day or two I start getting some zingers and electrical feelings in a nerve tract that is unaffected by my condition. I can only assume it is because it is getting stretched or compressed in some way, possibly at the spine. After the phenomenon repeated itself under the same conditions I quit pushing those poses as hard and the symptoms went away.
There are many ways that yoga benefits me or I would give it up. It even seems to help my affected areas but I do have to modify some positions and avoid some others entirely. Like any new exercise, approach it gently and listen to your body. Yoga can be much harder than it looks so go easy on yourself if you go ahead.