Today I took a look at version 1.8 of ditherig on my Win 7 PC (a NUC5i5RYK) which is essentially a laptop without a screen. My monitor (displayport out from the NUC to an active VGA adapter) has FRC, I always knew that. I was curious to see if this app would do anything.
Surprisingly, it does work. I was able to see movement changes in a gradient. These changes are subtle, because dithering is always active no matter what, but I was curious to see what would happen if I go double.. selecting temporal in the app caused the greyscale gradient to begin strobing a bit (busy static pattern). Each setting down to disable was calmer snow. The disable setting cannot disable it completely, because the monitor itself will always do it (plus whatever the adapter is doing as well) so I do not see 6-bit banding, etc.
My best guess is that Intel drivers do not default to temporal dithering, but spatio-temporal.