Okay so I can confirm this works great.
I removed the steam driver by running the following:

```
sudo find / -name "*Steam*.kext"
sudo rm -rf /Library/Extensions/SteamInput-DS4v1.kext
sudo rm -rf /Library/Extensions/SteamInput.kext

sudo kextcache --clear-staging
```
Then rebooting.

Now when I connect both controllers (im using bluetooth but should be the same), the game launcher didn't show anything but Apple MFI and the game is recognising both controllers perfectly no buggyness!

This is awesome! smile

For anyone who doesn't know what to add to the plist file or have Xcode here is the file I edited.

Download this:
https://pastebin.com/AVC81aNe


Rename to GamePadDefinitions.plist and put it in the folder of the Game App Package.

This is where the original file is located in the game app package.
https://imgur.com/a/TS6tbPa

The new entries in the plist are these two:
https://imgur.com/a/Uhgezm3