Excellent list, you've included numerous extensions I already use, and some new to me that are very nice ideas as well.
The only extension I use that you haven't included is Vitals - it shows various system info you choose on the top bar.
According to the comments, it needs an update for GNOME 3.34, I hope it'll receive it, as it's a nice extension.
There are some extensions I used to use, and I'd like to use, but no longer work 100% correctly as of GNOME 3.32 (Pixel Saver, Pixel Saver Fork, NoTitleBar and others). I liked those extensions, as they removed the title bar from maximized windows, and instead displayed the title bar content in the top bar.
I think it has something to do with the application menu being disabled in Solus in the top bar, as they worked by substituting app menu in top bar with title bar content (yes, I tried them with app menu enabled in GNOME tweak tool).