Spoken by someone who clearly does not have ADHD.
I can say that sometimes "things just work" and that's what I'm always searching for. The thing that makes me not feel like "I wish this worked just a little differently".
I used to fiddle with fonts all the time, until I found Monolisa. I haven't fiddled with fonts in a long time.
I've found that for task organizing I have to have 2 levels. My todo lists for various "modes" (work, personal, kids/house), then another completely separate list of things I make at the start of each day. Still don't know of a tool that does that and I've just stopped looking.
Admittedly, I still fiddle with themes, plugins, etc. for code editing. :x Always after that 1 theme that will help me see everything on the screen at a glance without angry text (red text mixed in otherwise subdued tones) and covers all the different file types I use, appropriately. Just typing this out is making me wonder if there's a way to apply a different syntax theme to different file types. Hmm, about to waste another 20 minutes to an hour looking into that, I'm sure.
TL;DR I think the other person that answered this yesterday said it better than me "it's not about numerical gain, it's more about making sure your shoes fit".