I've been considering a mod that adds minor cliff adjacency as a general benefit for harbors & Royal Docks & Cothons. sql is not in my skillset so I'm having a great deal of difficulty understanding how it's been implemented in this mod.

As far as I can tell, it's using coastal hills as being equivalent to a cliff, a workaround necessary because CLIFF isn't a defined terrain or feature. However, looking at maps generated by the game there are plenty of coastal hill tiles that aren't cliffs on any of their faces. I can't even discern a pattern like requiring adjacent coastal hill tiles to generate a cliff. I see strips of three consecutive coastal hill tiles that don't have cliffs and I see single hill tiles that do.

Is the workaround used here a rough approximation of cliffs that may over- or under-count the number of cliff edges represented in the graphics (and thus in the actual map code)?

TIA!