Procedural Runtime Landscape

From looking at all current posts about this topic, it seems to be pretty much impossible.
but is it true? because I managed to get half way.

I managed to change the heightmap of terrain using this:
for (int i = 0; i < Landscape->LandscapeComponents.Num(); i++)
{
Landscape->LandscapeComponents[i]->MarkRenderStateDirty();
Landscape->LandscapeComponents[i]->SetHeightmap(HeightMap);
Landscape->LandscapeComponents[i]->RequestHeightmapUpdate();
Landscape->LandscapeComponents[i]->PostLoad();
}

Though collision doesn’t update. Tried all other physics update methods, but those throw a compilaton error. symbol not found something. Is there a way to actually make this work?

This seems to do the trick (also need non srgb texture):
Landscape->RecreateCollisionComponents();

this doesn’t do anything:
for (int i = 0; i < Landscape->CollisionComponents.Num(); i++)
{
Landscape->CollisionComponents[i]->RecreateCollision();
}

also need to solve some crashes with mips n stuff. but this seems to do the job