Customize rangeslider handles / grab areas

I’d like to be able to customize the width of the area used for the rangeslider drag handles. The reason is that my users typically want to move the individual cursors (rather than “sliding the window”) and may be using touchscreens. The default target area is rather small for someone with big fingers.

Is this possible? I don’t see a relevant option in the docs. (thickness appears to refer to the height of the whole range slider control, not the cursor grab handle thickness)

See also Hide the handler/grabarea of rangeslider