FWIW, I’ve played with the heightmesh. It’s promising, still beta, but performance and tessellation-density can be quite good.
As well, it CAN be dynamically updated insofar as height, at a cost. Can be used with a capture/render-target on your player for depthmask to create footprints in mud/snow, paths in same, etc, etc. No collision, true, that is still driven by the underlying landscape, but it’s an option one can play with so be aware.