"I can't concentrate until it's gone"

Here's a practical objection. Whether or not the feeling would pass, it's in the way now. You can't work with the flicker sitting in your chest. The remedy clears it and you get on.

Some discomfort does block work. A headache does. Real hunger does. A worry with a deadline in it does. I'm not going to argue that every feeling can be worked through. But look at what the remedy does to the work. The biscuit takes you to the drawer and back, and while you're eating you're not working, and afterwards there's the second feeling, which is a small distraction of its own. The phone in the queue isn't work, but at the desk it's ten minutes and a lost thread. The remedy is a bigger interruption than the flicker was, and it comes with a return trip.

What I'd suggest instead is that a two is a background hum, and background hums can be worked through. Not fought, not fixed, just left running while you do the next sentence. You've done this before. You've worked through a slight cold, a stiff neck, a room that's too warm. A flat feeling at twenty past three is smaller than any of those. The belief that it blocks work is another untested forecast, and the test is one task done with the flicker present.

Notice too that "I can't concentrate until it's gone" has a hidden assumption, which is that the remedy makes it go. Chapter 4 is about why that's mostly the alibi. If the feeling was going to fall anyway, the remedy bought you nothing but a trip to the drawer, and the concentration you got back afterwards was the concentration you'd have had at minute eight without moving.

Try it once. When the flicker comes at the desk, pick one small piece of the job, ten minutes' worth, and do it with the feeling still there. Don't try to make the feeling go. Let it sit and work anyway. In my experience the feeling is gone before the task is, and it went while you weren't attending to it, which is the wave falling. The task got done, and there's no second feeling, because there was nothing to have a verdict about.