In a long (and highly recommended) talk with Digital Foundry, some Bluepoint Games devs revealed several technical features regarding PS5's Demon's Souls remake, also clarifying some doubts about the game. One such detail is regarding the two visual modes the game supports: cinematic, which runs at native 4K at 30 frames per second, and performance, which runs at 1440p and 60 frames per second with some 4K elements, like the interface.
As a curiosity, the studio representatives stated that they prefer to play in performance mode, and that Demon's Souls was always conceived as a 60 frames per second game, even if they wanted to include the 4K native option as well.
There were also doubts about the use of Ray Tracing, which the studio clarified - it does not use. As a launch game, which was in development for less than three years, the studio chose to use Screen Space Reflections instead (reflects only what's on the screen, while Ray Tracing reflects everything around), more for the sake of time than hardware limitations.
Either way, the result is incredible, and experiencing Demon's Souls at 60 frames per second on PS5 is one of the most "next-gen" experiences you can have right now.