@okulele Wow, thanks so much for your answer. Upon first read, this was almost like a little mini-awakening to me. Then I read 3-4 times to fully grasp it and the first effect was gone already
Anyway, I think this cleared it up quite a bit for me. I was tripping over passages in the book where he says e.g. "Ask yourself, what kind of emotions am I suppressing" or "Go into a situation mentally and see what emotions come up" which both sounded to me like more on the "doing" side. Perhaps the "not-doing" can follow after those exercise by letting go of whatever comes up, just as you described