I have done previous work on this and learned a lot from some guys here over a decade or so, so I got pretty far. At least as far as to get surf near beach, with wider waves offshore, but some things are still hard to accomplish, hence my quest for ideas. New guys around, so you never know
The most problematic thing is to get the normal off the coastline/beach and translate that into a (stronger) shear (or what you'd call it) towards the beach, like surf. Twist and shear, redirect, vector displacement, all work in a static direction, afaik.
Another thing is to mix two sine waves to get some variety from the basic straight lines (besides warping them a bit). Tried to mix sine and cosine, but they seem not to work together. Shifting them a bit by PF is awkward too, as the mix won't work very well yet. The soft max is therefore a good idea; it works nicely, and is an interesting addition.