Interesting, I didn't know of that option. I tried it,
Option "NoTwinViewXineramaInfo" "true"
but still the same issue - takes the two desktops as a single big monitor.
Regardless, Nvidia should do randr 1.2 and above.
Yes, lack of opencl is a showstopper for me as I use opencl/cuda for work. But I am optimistic it will be done in some time. (If not, hopefully I can contribute something to it after I am done with university.)