I like to run my lights on scatter guns as close to the muzzle as possible and as high as reasonable for me to hit the switch… all with the least number of parts to make it work for simplicity’s sake.
If you’re right handed I’d have the light on the left side of the gun.
I like tape switches but on a shotgun I’m rarely using a “C” grip over the barrel, ymmv.
I prefer a tailcap switch that I operate worth my left thumb. I know those SF pro’s rotate into position, I think you’d be happy with the factory mount on the side over the picatinny on top.