I know about the terrain additions, and even though the list is huge, just consider one thing: As of your latest decisions to switch to DX11 only, I'm assuming you're targeting mid- to high-level hardware, am I right? Those machines can perform tasks like that with ease (ok, with limitations).
When I linked the algorithm I didn't meant this should be implemented exactly but to cut out features not noticeable in the FPS pespective, like the Hotspot-Effect. In the end, it would just be an improved billboard alternative with little performance hit but great visual impact.
Another thing with negliable performance hit is the addition of a global perlin normal map, a global colormap and uv blending on the terrain. With uv blending I mean that in the distance, textures get an overlay of the same texture with uvs scaled up. That all add to great visual quality and least tiling..
A great example is RTP, which I already linked here on the forum I think. It's a good source on simple little additions to improve quality of the terrain (POM shading excluded, too complex). This is a screen using uv blend and global perlin normals:
I'd also like to ask if you could allow for adding and changing generation steps and their order using the modding tools. That'd be great and would allow me and other modders to implement more simpler things like that.