I think the X is running the same resolution as XBox 1 X in resolution. But its been a long timeFrom what I see the "resolution mode" is exactly the same between PS5 and PS4 Pro, i.e. they didn't patch anything on that mode.
And I bet the PS4 Pro / PS5 1440p modes aren't using the ultra settings either.
The resolution mode wasn't patched. Apparently all they did was locking the framerate to 60FPS on the graphics mode and call it "performance mode".