Earlier quoted context omitted.
Regarding scent, I definitely notice a difference in my Appalachian brain. I feel like the s sound is more drawn out with the present.
I wonder if this might be a mental artifact of being aware of the spelling. Kids probably would hear no difference between 'scent', 'cent', or 'sent'.
It's not always the case, but there can be a reason to believe that spelling differences may have arisen in such cases from trying to explain subtle distinctions that mattered to someone's dialect before a lot of the modern work went into the IPA and actually capturing those subtle differences.