Update: Very brief combat testing seems to work for now. I've gotten companion triggers as I walked around (lady recognizes one companion, assassination attempt, etc vagueness for minor spoilers) .
There's some funkiness with the character tab (right arrow cannot access 6th member, left arrow will constantly switch between 5th and 6th member), but it works well if you just click on the party member you want in the sidebar. All inventory is shown and works well.
Switching party member order in the sidebar works. Formations work in large open areas but in smaller areas the party sometimes clumps together since I don't think the AI pathing is used to so many people grouped together.
Feel free to use the mod but it might break your game as I haven't really tested it much. Will do further testing later.