Hello @lilotter, Welcome to Connect. Thank you for sharing your experience and what has helped you. You are right about it being difficult to find information on some of the more rare types of neuropathy. I did find a couple of articles using Google Scholar (https://scholar.google.com/) that are over my head but you may find some value in them.

Dysimmune small fiber neuropathies - AL Oaklander -- "… dysimmunity seemed eminently plausible given the well-documented immune-mediated neuropathies and links … in Boston for SFN associated with autoantibodies to TS-HDS and FGFR3 …
and trial existing and new therapies for apparently dysimmune small-fiber polyneuropathy …"
-- https://www.sciencedirect.com/science/article/pii/B9780128145722000108

Clinical characteristics of fibroblast growth factor receptor 3 antibody‐related polyneuropathy: a retrospective study --- "… fiber neuropathy associated with FGFR3 and TS-HDS may provide further evidence regarding …(INCAT group), Clinimetric evaluation of a new overall disability scale in immune mediated … Dave A, Smith J. Use of Intravenous Immunoglobulin in Small Fiber Neuropathy associated …" -- https://onlinelibrary.wiley.com/doi/abs/10.1111/ene.14180

Have you made any lifestyle changes that have helped?