I don't know if terrain texture is covered in that video, I think it's more about vegetation and lighting but it doesn't hurt to ask David or Nilla and be sure.

First time hearing about this plugin and yes I am using a displacement approximation node with the following settings:

Approx Method : Spatial
Approx Style : Fine
Min Subdiv : 4
Max Sudiv : 8
Length : 0.001
View Dependent: off
Sharp : 0.000

2 mins on my i7 3.4GHz 16GB RAM machine



Spatial has given me the best results without too much hassle, it gives me access to the "fine" approx style, the way it triangulates the mesh gives pretty nice smooth details(especially with the case of this high frequency texture) and even breaks up the object for less memory consumption.

Min/Max subdvision values clamp the degree to which the surface is tessellated.

Length value determines triangle size, the mesh will keep subdividing until either the edges of the triangles are no bigger than this value or it hits the max subdiv cap you've specified. Smaller values mean smaller triangles, more detail(and added rendertime!).

View Dependent is tied to Length. Checking it on tells the renderer to see edges in pixels instead of object space, so it will keep subdividing the mesh until the edges are no bigger than x pixels(determined by Length value). This can be handy since, edges that are far away from or unseen by the camera will not be finely subdivided and you can get away with larger Length values. I've found a few issues with it though, like blurring in some areas and bad artifacts with other approximation methods.

Sharp controls the smoothness of the surface, a value of 1.000 will result in a faceted appearance.

I'll be honest, the UI could be a bit more helpful, especially with something as render intensive as displacement, it took a lot of trial and error but I'm getting there!