If your doctor will treat your SFN based upon 'clinical' findings, then there is really no sense in having it done. But most doctors don't do this and/or insurance won't cover the treatment unless you have proof of SFN (and skin biopsy is the ONLY proof). So, YES, it can and will change the way your condition is treated.

Not to mention, that the skin biopsy is an excellent way to gauge progression as it can be repeated down the road to see if your treatment is working.

But if you cannot tolerate the procedure, then this needs to be a consideration and other means of performing the test explored.