Grass fades out nicely, but LOD transition is still harsh

In the landscape grass type of material that you have to create, you can find a setting for start cull distance and end cull distance, which can make the transition from grass to no grass very smooth and nice.

But I have not found a similar setting for the transition between LOD levels, and that transition is very harsh and ugly.

Can anyone tell me where the start LOD and end LOD distance is?

I do hope Unreal supports a similar nice fade for LODs.