(Never give up!..) :)
Same problem here with NVIDIA GeForce GT 520M (10de:1050) GF119 under Sierra 10.12.x.
But, someone with GT 540M & GT 615 (GF108, Fermi, non-Optimus) got it to works.
I have no more ideas, just recently did some tests by replacing my 10.12.5 Beta's "CoreDisplay" binary...