Was quantiferon negative all 20 years except one time after the covid ?
I will look for an article i came accross few years ago and will upload here.
In regards to your question " will you ever not need an annual xray" - the answer is "it depends" each work setting has its own guidelines governed by Department of Public Health and Infectious Disease MD.
I would recconend finding their phone numbers and speaking to both. There should also be annual questionairre that we all do for tb surveilance/clearance that prompts our employee health departments for xrays, sputum tests, etc. If you are answering Yes to any if these questions, that might be another rrason why you need annual xrays.
In retrospective - we get 100 x more xrays just catching 45 min flight (SF to Los Angeles 🙂 than one signle chest xray. and At least you are not being asked for AFB sputum 🙂