Confirmed they working on a VRR and 40fps update.
'' Additionally, there’s a new Herbalist vendor who sells animal parts, and we’ve revamped Temporal Anti-Aliasing to improve the visual fidelity of our Performance mode on PS5 and rendering on PS4 Pro. We’re already working on an upcoming patch which will include VRR support and a 40FPS Mode, so stay tuned for more.''
https://www.google.com/amp/s/blog.playstation.com/2022/06/02/horizon-call-of-the-mountain-gameplay-trailer-revealed-and-horizon-forbidden-west-gets-update-including-new-game/amp/