Hello @atlas, welcome to Connect. I have small fiber PN but had not heard off Orthostatic Hypotension. I did find some information on the National Organization for Rare Disorders here:
-- https://rarediseases.org/rare-diseases/orthostatic-hypotension/

I was recently diagnosed with lymphedema due to some swelling in my legs so now have to wear compression socks. Have you considered going to Mayo Clinic Scottsdale? I’m not sure if it is an option for you but if it is, the Mayo Clinic is very good at diagnosing health issues that are difficult to diagnose. If you would like to seek help from Mayo Clinic, you can contact one of their appointment offices. The contact information for Minnesota, Arizona and Florida can be found here:

Mayo Clinic Contact Information: https://www.mayoclinic.org/appointments

John