Not sure of your age, but 20% of over 60 year olds do not absorb B12 properly (although this doesn't mean that they are deficient) so B12 deficiency common and twice as common if on metformin.
I would also get your Vitamin D level checked cos that is associated with neuropathy, although most UK residents are deficient. And also throid function cos underactive thyroid can cause neuropathy.
At end of day may not find an abnormaility or might find an abnormality but the neuropathy is due to the diabetes, but it would be silly to miss something treatable. Yes - it is said that the pains occur when the nerves regenerate - I am not sure about this, but one agent that was good for nerve pain, sorbinil, was found to be poisoning off the nerves so perhaps there is some merit in this line of thought.
Neuropathy is a moving target - trating my B12 and Vit D deficiencies has marginally helped, but it would be worse if I had ignored the problems
best wishes