I've been trying out the 4 player "Mod". The initial instructions seemed plenty to get it working. I can say, it works! I popped my connection mode to anyone and 3 people joined. We each had free control of a character and combat worked completely fine. The only issue that someone claimed they were unable to see their skills and health bar.

Now that's all fine and dandy. Good Job. 10/10

Later the same day my little brother wanted a go of divinity, I was like hell yeah pop that into split screen mode and we gonna get funky.

Played through the start of the game, got to Cyseal market and it said someone had joined? Oh.. ok.. cool. Kept playing, the guy was like "Can I play? How do I join? Can I be Jahan?" however it didn't show anyone in the assign character screen or connected players screen. I was unable to type to him (bug with controller mode?) and he left. 2 minutes later, after we got Jahan and Madora, we noticed someone else trying to join. I went to speak to Thelyron, just doing that first bloodstone quest and that, came back to cyseal market place to notice someone had joined as Jahan and went on a killing rampage in the marketplace. R.I.P Cheese man.

TL:DR - It also works using split screen PS4 controllers, you can't see connected players and cannot assign characters to them. Please feel free to disregard what I say if someone finds a workaround.

Thanks for all the hard work in getting this working so fast. :)