Found something else yesterday after rabbitholing down the steam forums. Now you solved your problem already. But hopefully that keeps it from coming back.
Currently there seems the a problem with PowerTools installed and the Game.
So if the game is crashing after the Nvidia logo (on experimental or hotfix) try to remove PowerTools and restart the Steamdeck.
Found something else yesterday after rabbitholing down the steam forums. Now you solved your problem already. But hopefully that keeps it from coming back.
Currently there seems the a problem with PowerTools installed and the Game.
So if the game is crashing after the Nvidia logo (on experimental or hotfix) try to remove PowerTools and restart the Steamdeck.