Also you'd think you'd be able to limit alt the same alt as the plane/sphere with a distribution node, and then warp it back up by the water displacement at the same amplitude, but it doesn't align right, and none of the transform settings will align it right that I can find.
Here is an exmaple of the issue. The displacement is inverted to follow the water level, but it seems like some of the secondary mixed noise is not read correctly or is inverted because of using -1 disp (or complement scalar) which then makes the fine details of the water out of sync. Or so it looks. Maybe
@Matt can weigh in on why exactly it can't line up perfectly on the micro disp level. Edit: it aligns much better with PF noise based disp (not inverted), but still not perfect down to fine details of the disp. Follows the larger shapes easy tho.