Update: I see in the comments that if you set the "height" of the titles 50, you get multiple lines for the titles - and I can now see the plus-sign (+). I suggest this to be documented somewhere in the GUI, because I would never have guessed this functionality.

Quite good, lots of potential and just need some polishing and additional functionality.
Plus - The good things
+ Has a working import for the old Speed Dial by Josep del Rio, which recently stopped working with Firefox Quantum. This saved me my 1000+ old Speed Dials!
+ Can open dials in new tabs in the background. without switching to them.
+ You can "scroll-change" between groups, so you don't even have to click on the group titles in order to change group.
+ You can change the size group titles
+ Fast

Minus - what I would like to change/add
- Where is the "+" button at the end of the end of the group list? It's never visible, at least not in in FF Quantum.
- I would very much like to be able to scroll through the group list with "arrow buttons" as is possible in Josep del Rio's Speed Dial as well. Yes, I know you can "scroll-change" between them, but then I never see the name of my "current group".
- I'm eagerly awaiting time-based "Auto Reload" and the "Visual" functionality. Please do them similar to how they work in Josep del Rio's Speed Dial and I will even consider becoming a "Patreon"! :-)