Jason,
You've come to the right place for frank discussions of SFPN, prediabetes, polyneuropathies, etc. There is a wealth of info on this site and as people have noted much of it is not generally known and or recognized. I looked up your doc @ UPenn, I'm not familair w/ him but I also go to UPenn and my experience has been much different and more positive. If you seek a second opinion I'd push hard for Dr. Mark Brown, the dept chair - his specialties are diabetic and prediabetic SFPN.
If you want pm me and we can discuss in more detail offline. I'm sorry for your plight PN sucks at best but it's nice to have someone in the same general area to talk with.
Best of luck to you.
Alkymst