The instructions provided worked great for the most part for getting this running on Steam Deck. They worked perfectly for running in Desktop Mode.
However for Gaming Mode, it always opened the Launcher in such a way that I was unable to access the window to hit 'Play'. I amended WineLaunch.bat to change 'Launcher.exe' to './Retail/HITMAN3.exe'. After this, it launched the game window directly and worked for me in Gaming Mode.
The instructions provided worked great for the most part for getting this running on Steam Deck. They worked perfectly for running in Desktop Mode.
However for Gaming Mode, it always opened the Launcher in such a way that I was unable to access the window to hit 'Play'. I amended WineLaunch.bat to change 'Launcher.exe' to './Retail/HITMAN3.exe'. After this, it launched the game window directly and worked for me in Gaming Mode.