For Mafia 3 specifically, file patching is actually the cleaner approach — no DLL injection, no Defender issues, works without the game running, and the game has no integrity check or active updates that would revert the changes. Hooking would make more sense if the game verified its files on launch or was actively updated.
It's possible to force the game to use windowed mode but it has some issues. Set these values in dgVoodoo.conf
FullScreenMode=false
AppControlledScreenMode=false
DisableAltEnterToToggleScreenMode=false
I just now saw this, Sorry. I tried that just now and It didn't work, but I didn't stop there.
I did some research and it is actually the valve_addon folder and Allow custom addon content must be checked in the settings.
I will be updating the instructions as well as compile the latest revision and provide a version that works with Retail Half-Life also when I get the chance.