At The World Forum, one of the Japanese architects talked about this subject... I think he mentioned that there were 2,500 courses in Japan, almost all of which used the double green approach at one point (grasses, seasons, as above)... And that the last 20 years have been spent changing to the one green approach... so that there are now about 800 courses left with double greens...
I stand to be corrected on these figures but that is my memory...