I take the tape off after I've spooled the film onto the reel. I do this because I don't like the chemicals seeping under the tape and not being fully rinsed out in the last step. My last step is four fill and dumps with progressively more inversions between each f&d. Also I don't like the feel of peeling off soggy tape !
I wonder why peeling off the tape would only emit x-rays in a vacuum and not at atmospheric pressures.