What inspired this wish list request?
A column switcher with many columns requires scrolling up/down the list box of columns, and a simpler way to do this would be to use a combo (drop-down) box.
What is the improvement you would like to see?
I would like to have the option, similar to what you can do with the data filter, to switch the selection display box to a combo box (Single Variable Display) or a radio box.
Why is this idea important?
It provides more UI options, and I find that in some situations this makes the column switcher easier to navigate. It also makes the chosen column more obvious in the report sometimes.