I use dodge and burn quite a lot in gimp - and the usability could be greatly improved ;o)
The main variables that I change all the time are
Deckkraft
Grösse
Typ (abwedeln/nachbelichten)
Umfang (schatten/mitten/glanzlichter)
The former two are on top, the latter two are on the bottom of the toolbar - it is an eternal scroll-up and scroll-down - also because I can NEVER see what type of modification is active when clicking on that tool - I have to scroll down all the way to see if highlights or lowlights/shadows are active, if dodging or burning is selected.
I would so much love to have those four choices all at the top so the tool’s settings would be immediately clear AND that scrolling could stop.
The main problem is that everyone has different preferred/most used settings on various tools. You can’t imagine the bugs we have where people will tell us how option X or Y which are at the bottom of the a options should obviously be at the top while someone else will say X and Y are completely useless and we should put Z at the top.
And of course, if we do any change, we always get angry people shouting at us because previous option layout was perfect.
My solution would be that tool options should be customizable (like drag’n droppable widget to reorder). I know that some people don’t like the idea, because then you find various videos and screenshots on the web with all kind of layouts and many people end up lost. Yet (1) we don’t do features based on how random video tutorial “streamer” do their job (2) they can/should likely just reset their GUI when they do tutorials (3) considering it seems impossible to satisfy everyone with a given order of options, it seems to me that making this customizable is the only good/efficient solution anyway (defaults are still important, but then we can stick to “good generic defaults”).
So yeah that’s one of the GUI improvements I have thought about for a long time now, but never got to implement it (and anyone is welcome to do so before me and propose a patch by the way! I have a lot more stuff to do anyway).