When installing Cathedral Landscapes, if you select the 'grass only' option, there are still other non-grass things installed. For example; snow lod, plants, material objects, etc.

I've removed all non-grass features, as well as incorporating the changes from my 'no floating ash leaves' mod.

Brown tundra version only.

I've included the Cathedral tundra landscape textures as an optional download, which "has had grass and other ground cover baked in so your grass will blend seamlessly into the distance".

I recommend you also use Cathedral Landscapes Grass Mipmap Fix, overwrite  Cathedral True Grass or merge.

The screenshot is with grass LOD generated with No Grass in Objects.