Personal anecdote: describes me, may not be at all like everyone else:

Write down answers to the existing refining/priming until you can't think of any more and you feel a slight bit of mental exhaustion. This allows you to feel confident that you aren't going to waste any of the effort you started doing when you accidentally entered refine mode. Save your writings. It doesn't have to be finished or grammatical, and you don't have to post it, but you sort of give your brain the mental signal "I've saved your work on this refining this topic and will be able to use it later."

Do something unrelated which refreshes you mentally. and allows you to refocus your thoughts.

Start a new from the problem, attempting to think wide again. Do not look at the old document.

The futile part for me is attempting to think "Bad brain! Stop that! Get out of refine mode at once and back into wide mode!" That just wastes time. where I counter with "These ideas are relevant and I refuse to forget about them until you acknowledge them!" It's better to simply do a speedy "Refine draft" of what you have been primed and anchored to, and then start again.

Actually, now that I've laid out HOW I do this, I now have a desire to actually time myself to see how fast it is. I mean, it feels like the best solution in my head... but it should at least be theoretically testable. I would imagine there would be a lot of confounding factors.