Currently, "Selection Set" (Preferences- View options) is only for color. I would like more parameters to set it: transparent, etc...
Even different behaviour according which element is selected. For example, if an element has Fill or pattern, I would like more transparency.
I say this because if we select a circle or polygon which has a pattern, the color of "Selection Set" hiddes the pattern of the element and although we have open the properties window, if we set the pattern in the properties, we can't see the properly result in the drawinguntil weunselect the element.

I like how AutoCAD shows the selected elements without hidding the patterns or at least, minimally.