There's no forum feedback section, so I post it here.
So I think the Dark forum theme is not dark enough (for me) and some of the graphics are not good. So I did some css edits and implemented these on the forum via the Stylus plugin for Firefox (or Chrome). There are other solutions to directly alter forum css, but I will not go into that for now.
To make it look properly you have to first activate the default dark theme of this forum (which is weird enough not the default theme), if you've not done that yet (scroll to the bottom middle part of the forum, where there's a pulldown menu called theme).
Here is my current code:
You can try it out and see how it looks.
It also improves the looks of the like buttons on the side.
I keep tweaking it and updating this post, so it might not completely look like in the supplied screenshots.
Summery of extra custom edits that are more opinionated: