First of all, I am using Watchout 5.
As a follow-up, I got results which made me happy with H264, as long as I chose the options Fast Decode.
To summarize, this is 4 computers, with 4 displays each. The resolution of video is 5120x3840.
In order to save space, I tried to ask for the movie to be split such as there would be one video per computer.
However, since the cut is not even horizontally nor vertically (each block limit crosses other block in the middle), and H264 worked good, we did not follow on this.
Thanks, but I am on WO5
I'll note the suggestion though