I’ve never had an issue with a non-torch zippo lighter when going through TSA checks. Ive never had an issue with a zippo while going through airport security checks in Japan. I’ve had non-torch zippos confiscated while going through all the following airports: LHR, CDG, FRA, HAM, BCN, MAD.
Most airport security is theater sure, but the most egregious theatrics haven’t been from the TSA in my experience.