You can specify the minSize and maxSize for the circle size on a bubble map, but you cannot specify the z-min and z-max values that should correspond to those sizes, effectively dictating the distribution.

The goal is to be able to add a legend to the map that displays the z-min value and minSize circle as well as the z-max value and maxSize value, but right now that cannot even be rendered manually since the association of the z-min to minSize and z-max to maxSize is hidden.