I don't know about BC/BS and the surgery issues, but I do know I'm listed as a tobacco user with my current life insurance and I had not smoked for 3wks before they did the saliva test. Like the DNA swabs you see on TV. Cotton swab in the mouth.
I was looking at switching companies and the lady told me at least 30 days off nicotine if I wanted a chance at passing, but 60days should guarantee it. How accurate that is or whether it's actually the nicotine and not something else, I can't say. That's just what the insurance lady told me. HTH
Forgot to say I've had many issues with BC/BS over the years over a range of things. Things like refusing to cover my son's birth because he was too old to be listed as a dependent. Now I was 21 at the time and this was the charges for his birth. They kept insisting he was something like 64yrs old. Rather than just fix the error on his DOB that whoever had made when they entered it into the computer, I had to physically take him into their offices so they could inspect him to verify he was indeed a newborn infant.
Once they finally fixed the error they told the doctor's office to resubmit. When she did they then denied the claim saying the doctor had waited too long to file. Good luck with them.