The current upscaling options (TAAU, BILINEAR) on ps5 generate an incredibly blurry image while not providing any improvement in the fps performance. I dont know if it's bugged or just not properly implemented.
To circumvent this, I suggest to have the game render at a lower than 4k resolution when connected to a non 4k screen, i.e, if the ps5 is connected to a 1080p monitor (or if the user manually changes the console output resolution in the console settings to 1080p), have the game render at native 1080p instead of 4k like it's currently happening. This would significantly improve performance and provide stable 60 fps and allow all current gen users (xbox series x and ps5) to enjoy Vibrant Visuals without a laggy experience.
Forgot to mention that I’m playing on a 1080p monitor. The image I’m getting using TAAU at 75 is very blurry, blurrier than normal 1080p. I don’t know if the same is happening when playing on a 4k screen.