There is only one "treatment" today --actually two.

IVIG and Rituxan for severe autoimmune demyelinating PNs.
These are horrifically expensive and only work for specific cases.
Sometimes even they fail.

Symptomatic control is not really "treatment" as it does not typically
change anything, only provide some if any, relief from discomfort.
The trade-offs for symptom control typically are high and other side effects can be significant. Doctors can offer these drugs, like gabapentin etc, and that is about all they will do.

What you get from a doctor is a "diagnosis" if you are lucky, that will point you in a direction where you may be able to heal yourself. It is the very rare doctor who can help with healing.
Mostly that is up to you. There are some neurologists today who will suggest lipoic acid or acetyl carnitine. But they are the exception rather than the rule.

If you have a gluten intolerance or other food intolerance or continue to expose yourself to whatever the trigger is, you will continue with the PN and possibly progress.

If you have vaccine reactions, and continue to get vaccines, you will continue to have PN.

Hereditary genetic causes, at this time are not understood well at all, and interventions for those are unknown.

If your blood sugars go up and down suddenly and consistently due to consuming alot of sugars, you will always have sensory symptoms.

The longer you have a metabolic PN, the longer it will take to help heal it. Shorter PN time frames often give faster results when healing nutrients are tried.
My PN in the feet and hands took just over a year to get better with thyroid hormone. All that time I had endless tingling as the numbness wore off. That is just one example, that was my experience.