Which Holosun optic is that on the Elite? Did you need adaptor plates? I have the same XD elite in 9mm.
https://www.springfield-armory.com/xd-series-handguns/xd-m-elite-handguns/xd-m-elite-45-osp-threaded-9mm-handgun-desert-fde/ .
I was considering the Holosun HS507C-X2 Reflex Red Dot Sight...