Change radius and size values (QOL)

Why are the values for brush sizes different in the ‘tool options’ tab and the ‘brush editor’ tab: in both tool options and brush editor the size of brushes can be adjusted with sliders, in tool options its by ‘size’, while in brush editor its by ‘radius.’ When I adjust the ‘radius’ slider and reset the brush size in tool options their numeric values are different and when I look at the max values in both sliders they are also different.

If these two sliders both change brush size, then why aren’t their sliders use the same magnitudes?

The brush editor is for parametric ‘x.vbr’ brushes and goes back to Gimp 2.6 and earlier where there were no brush size sliders but sets of ‘sized’ brushes. (still there in /usr/share/gimp/2.0/brushes/gimp-obsolete-files/)

The brush size slider modifies the displayed size depending on the ‘native’ brush size. The size you get by clicking on the reset icon next to the slider.

Duplicate a vbr brush so it is editable. Edit the radius to change the ‘native’ size. The size slider then reflects the change in the brush ‘native’ size. The tool options slider does not edit the brush.