Thanks for the input, I’ll travel tonight. For the record, I wasn’t worried so much about the safety of the ride as about damaging other items of mine that I might be carrying along with the magnet.
I brought home a tin of rare earth magnets from Burbank last year. The tin contains 52 magnets, from 1/4" to 1". I stuck it in a bag of dirty clothes in my carry on and said nothing at TSA, I didn’t think it was a problem. Neither did TSA, I was waved through without question. The tin weighs a bit over a pound and requires some effort to remove it from a steel surface.