thanks for the screenshots. rustatorium seems to have double the performance gain by going to 51.75 from 45.23.
its too hard to see what have been changed in rustatorium with 51.75 by just judging from your SS, they are taken with too different positions. but i hope it is not another IQ compromising optimization. i am not too nitpicking on IQ, but you are going to get worrying performance on many siturations that are not optimized by nvidia.