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Your question addresses an issue that has been researched in animal studies. In general the primary effect of nicotine exposure during the healing of a peripheral nerve injury is to
increase mechanical sensitivity.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1948068/
"There was no difference in the rate of nerve recovery based on walking track analysis in the smoke-exposed animals compared with nonexposed animals."
https://www.researchgate.net/public..._on_Recovery_After_Nerve_Crush_Injury_in_Rats
So, tobacco exposure during healing may make the healing process more annoying, but not delay it. You'll just be more aware of the injury while it heals.
The online suggestions to quit tobacco use in order to improve healing of peripheral nerve injury seem to lack any references to appropriate research results, and are most likely an expression of opinion on the part of the author.
Bob