Cliff displacement/extrusion for more realistic cliffs

an heightmap won’t draw vertical pixels.
using houdini you would end up with meshes as well. You can’t sculpt on it like the terrain.

You can try to create a single tile landscape and turn it by 90deg. That’s about the only way to use the landscape and get detail. It’s not impossible, but why bother? A single tile is essentially a huge mesh.
You could benefit from cutting it up anyway.