"HAS SOMEONE TESTED THE MAX FRAME RATE AND RESOLUTION OF BC GAME ______ ON THE PS5?"
Anyone asking that question simply needs to look up the game's PS4 Pro targeted performance
in this Era thread and you will have your answer.
If a game in that thread targets 30 fps on the PS4 Pro, on the PS5 it will pretty much lock at that fps. The same is true for a game showing 31 fps or more on the list, it will try to lock at 60 fps on the PS5.
The game will play at the max resolution shown on the list, except instead of being a dynamic (fluctuating) resolution on the PS4 Pro, it will likely lock at it on the PS5.