Gene
All the 10m competition that I know of are ALL non-optic sights.
But if you shoot at home for fun, use what you want.
Personally, in the standing position, I find that I have to use the LOWEST power scope. The reason for this is WOBBLE. The scope magnifies my wobble, and the higher the magnification the worse the wobble looks. And for me, that also causes a visually induced motion sickness.
For fun, I've shot a 12x on my FWB-300 from a bench, just to see how small a target I can reliably hit.
My next is to get a higher power scope for that rifle.
Gary