Is there any chance you remember where you learned it? This was the only source I was able to find (there may be more out there, and it’s from 2015… which was nine years ago, holy fuck that’s weird) and it doesn’t seem to confirm. Still, there were a bunch of other articles that came up about how smoking causes impaired wound healing (which would make me think it’d make it harder to reattach a finger, so I have no fucking clue lol), and obviously smoking is bad for plenty of other reasons too. TIL about the wound healing though, I didn’t realize how much smoking affects the whole body. Yikes.