Quad Split Monitor view for temp burn-in

I'm working on a feature film where there is a lot of surveillance footage/monitor burn-ins. The Editor wants me to do temp burn-ins of some of the footage, but have four feeds split up onto a single monitor (quad split).

I have done the Multicam function, but when I try to add a 3D Warp affect to it, the quad split appearance disappears.

Does anybody have any ideas?

Thanks,

MD