I like to take my cassette apart to really clean it every few weeks. I have a problem with getting multiple uses out of lock rings. You tighten to 40 nm. Which is a significant amount of torque. Sometimes before I “get there” the lock ring strips out and hence I need replacement. I think I actually got better longevity out of a 105 lock ring—which as I recall was steel, not aluminum as Ultegra is, but whatever, cassette lock rings aren’t going to throw my budget out of whack.