Today I am adding Pappy's Pub by @Shessar:

And here's Sue's Town Hall:

Personally, I've just used them as visual aids and planning aids (but then again, that's what I use most of the maps for). Isometric isn't the best for battle maps, but at least in my world, battle maps are in the minority anyway, illustrations and planning tools are much more important, and for that, isometric gives a very nice easy to understand view of the place.

One I used recently was an outside view of a ruin

Wyvern's new holiday location is now alive in the atlas. Thanks for contributing these interesting maps.

The problem you are encountering here is that there is both an outline and a landmass. When you use change properties, you end up changing both of them (or all 3 in this case). You need to select just the land poly.

In your case, the easiest way to do that is when using schange properties to select the landmass by the edge of the inner lake, instead of the outer coastline. There should only be one entity there. This saves you from doing other tricks to select only the right entity.