Maybe I just missed it while browsing the settings but I can only adjust the brush selection by flipping it to the other side (also changing the other bar)
I would love it if it was more similar to blender and I could have the brush options on the bottom as it would be significantly easier and faster for me.
While this is not possible for the Toolbox itself, you can add a custom menu and put it on the bottom!
Shameless self plug that does explain some of what you might want 
ily
thanks so much! Hopefully we get a more expanded UI settings menu. I came from blender so its fucking with my muscle memory