Comment by OneMorePerson

I don't think what I experience is the exact same (maybe a different intensity), so I don't know if this will make sense.

For me caffeine makes it a lot worse, I'm pretty sensitive, on a lot of days I can't even drink a cup of coffee or it'll affect me. I also get a lot worse if I am letting a lot of tasks build up and I bounce around between them.

Ultimately what worked for me was developing the ability to not react to something crossing my mind. Like in your example right when the micro idea would cross my mind after going deep, I'd just let that micro thought have a few seconds to pass through my mind, and not react to it. I wouldn't give into the thought "I need to start doing this micro project!" or have any kind of reaction. Once the immediate reaction passed I would decide whether it's worth changing my focus.

This can also be used in the inverse, if I decide to go deep on something, periodically checking in to see if it's still worth going vs asking for help/input.