I kinda have to fully agree with this. There is not much you can do. Moving few calculations from pixel to vertex shader, and getting rid of dot product for heightmap channel selection, and a few minor ones, but otherwise it is all the same across different implementations.
Where the difference comes from? Firstly, you have to branch out pom in a such way, that it is only calculated for few meters in front of the camera, and not on entire terrain. Secondly, you need an effective approach to blend several POM layers. I also have an impression that I saw POM steps were hardcapped in CE.
Thing is that having POM on terrain takes more effort and it is impractical to do it in material editor only. It does not cost more in UE4. Doing self-shadowing needs even more work. Frankly saying, I did not invent anything better than using gbuffer custom data for POM self shadowing.