I agree. I would not retain curved sides or what is exposed in central disk or textures sets presentation.
I just mean that is a good idea to take inspiration of the mock-up.
Switch between brushes is an important point of workflow.
jfmatheu proposal did not follow the rules of most neutral presentation ; but it was not out of scope.
I don’t understand what you mean by layout.
When Ton is talking about
What is it, if it is not layout ?
A lot of Silex’s mock-ups are showing panels and pie-menus displaying 24 or 30 brushes of a custom sets.
Display of a custom set is a patent lack in current official blender, only satisfied by addons. We should have that present as default.
And that is only possible if currently layout is improved to allow it.