Those who know it 'does' diminish backspin keep their cue as level as possible and draw more - others who don't do that draw less. It's not moot to either.
If you mean the one pictured below, I don't know how it's supposed to be used, but tip/ball contacts outside the blue line (halfway from center to edge) are in miscue territory. If the lines are intended to show where the cue's centerline is, then they might all work except the red one.
pj
chgo
Yeah that's it. My brain locked up as soon as I saw this thing. Damn this VB won't quote pictures. No dragging either. Getting your images off my desktop. Hope you don't mind.