This is entirely down to the HDMI Forum, who blocked AMD from supporting 2.1 on their Linux drivers. There's nothing Valve can do until HDMI changes that decision, please point your pitchforks at the people responsible
www.phoronix.com/news/HDMI-2....

It's not cheap, but the Pwnage Ambi is pretty sick, you can change which side the side buttons are on, making it left or right handed at any time, neat if other people ever use your computer

I'm a Serious Gamer(TM) and I've fallen in love with the G-Wolves HSK Pro for FPS, feels like I'm aiming with my actual hand instead of a mouse. But I feel like I need to get a vertical mouse for casual desktop use tbh

they specifically mention on the playstation blog that the game has 2 models for dlss rr, it's pretty safe to assume that means the new transformer model