Do the Composition to the final result : 2304x3072
Then scale the layer to the 192 high...
then I see a way to animate the transform to move to the right then jump down and start at the begining again.... (width of the video and the speed is a ...
The way is to split the signal after its finished ;) So i.e. you output 1 4k Signal and split it into 4 times 1920x1080....
So you allready got 4 outs... Then it depends what your GPU can handle... or if you may can sacrifice some resolution and 1280x720 is maybe good enough...