Watch out, that only certainly works on frogs that have had their brains removed :D. The rest is still debated, but most experts are pretty sure it doesn't work. Though most places of work aren't known for their brains.
When I was a few years from RE (we RE before reaching FI, so we did things not like most people) I starting curating what I was doing. There was SO MUCH work and it was important but not urgent. Some of it was just to make the boss look good, or wrap things up that people that were laid off left behind, or cross training or etc etc. The company was merging then splitting so there was all kinds of drama and random going on.
Boss (after talking to his boss): I want you to work on x and wrap it up.
Me: I thought you wanted me to work on active project A and keep it moving forward to hit the deadline for submission?
Boss: I do, that is most important.
Me: Okay, so I will prioritize A, but that means I wont have time for x.
Boss: But I'd like x to get done.
Me: So you don't want me to get B done by date?
Boss: no we need B done by date.
Me: Okay. I'll work on those two projects.
Boss-- realizes he has no ability to actually dictate the over 35 projects that have come under my umbrella when we went from 60 staff down to 20- many of who are managers.... X was so far down the list, I was never going to get to it. It had been on no ones to do list for years, and was not going on mine.
Mine wasn't subtle like you were talking about. My avoiding cross training was slightly more subtle. After my group imploded and got moved to another state, I moved departments instate. For a year and a half before I REed, I was there. For most of that there was this special training I did not want to do for work. I really did not want to do it. I managed to avoid it by being busy, etc. Finally in the last few months I finally told the trainer, I'm retiring soon, it will be a waste of time for both of us if I learn to do this.
Apparently I don't do subtle well.