I found, changing the lua to have values rather than words fixed this issue for me.
So for you, write width = 3840, rather than screen.width / 3, and the same for height = 2160.
Write the aspect as 3840 / 2160
x = 0 for left screen, 3840 for centre, and 7680 for right.
y = 0 for all 3.
ViewDx as appropriate, probably +/- 1.05
And the last line should be UIMainview = Viewports.Center
Delete everything after that line.
Also, your ingame resolution should be set to 11520. The 11580 you have wrote above seems odd. Oh, and run the game NOT in fullscreen, and dont use NVIDIA surround.
This is what works for me now.
