The function of this mod is to fix morphing effects visible along coastlines. Coastlines have been reshaped using high res data and adapted to avoid terrain morphing. The mod do not alter terrain mesh other than those along the coastlines. Negligible frame rates impact.
I give this mod 3.5 stars (they don't do half stars here and this is better than 3 stars). The main problem is really Asobo's water masking, but until that is fixed, using coast morphing requires compromises or a water mask needs to be included (adding to the cost).
Pros: Offshore rocks are no longer flat, they have height and character. Where Asobos coastal data is limited resulting in ruler straight coastline segments, this product rocks, restoring the natural variations!
Con: A lot of water climbing the shores, not very far (a few tens of feet), not like the old days when it was hundreds of feet. Still, quite noticeable if you are flying under a couple of thousand feet and a deal breaker if you are sailing on the water.
So, until Asobo finally fixes their climbing water or a companion water mask product is released, I'm not going to run this mod. But I truly look forward to running it one day, the rocks and natural coastlines are winners. And, with the awful state of the Alaskan panhandles coast, I may well buy and install Taburet's Alaskan Coast Morphing Effects Fix even with the current compromises.