Yup but worth it and not really that much of an issue on nvidia gpus unless you refuse to use dlss and frame gen.
Well with the devs roadmap announced there, seems this will have to make do, doesn't look like HW RT will be anytime soon now.
I've installed that mod and then gone into the config and set everything to what he recommends plus the scaling options to what he recommends if you have powerful hardware.
Without FG I need DLSS balanced to get a steady 60FPS, FG boosts this to 100-110. It's very playable and looks amazing, but it's really making my 5090 sweat which I wasn't expecting

The two items I was hoping for on the roadmap was hardware RT and New Game Plus
TBH, New Game Plus is more important to me because I've gone to a lot of effort to have a nice full stash of everything I can ever need and I'd love to play through again and use it all against scaled up enemies