Firstly, +1 on Ego Depletion Depletion. For myself, I was never comfortable with believing in ego depletion, partly because it felt like a self-fulfilling prophecy (“oh I worked so hard this morning so there’s no way I can resist this chocolate now, I may as well just eat it and all its little friends”).
Also +1 on Atomic Habits at 6:56 in this video. Such a good book!
At 3:56, the video describes the experiment where a beeper asks you randomly throughout the day if you are resisting a desire, how strong the desire was, and whether you were successful. It occurs to me that you could do that experiment on yourself by using TagTime with the tags set to yes/no, weak/slightly-weak/strong/very-strong, success/fail. Whether you’d find that useful at all is a different question. 
Only slightly related to that but OMG THIS IS THE BEST BREAKTHROUGH FOR MYSELF and I’ve just thought of it now because of that part of the video so I have to share:
I can use TagTime for something I’ve been wanting to set up where I try to control how much time I spend staring at my todo list, frozen in indecision and horror, being unable to JUST START ON ANYTHING. I can use “frozen” and “not frozen” tags. If I know that a ping may come up and that I am beeminding the “frozen” tag, I may just be able to kick myself into starting more often. (Heh heh: “starting” as opposed to “staring”. That’s probably going to be munged to make the goal slug. 
)
And finally as a totally frivolous comment that I can’t resist making:
Looks like they tried the marshmallow experiment (“If you don’t eat the marshmallow now, you’ll get two later”) with two kids in the same room. A properly clever child should take the other child’s marshmallow, eat both thereby getting two straight away, and of course the other child must be given two later because they didn’t eat their one. MARSHMALLOW PAIR SUCCESS!