Yes the Nanite displacement maps are working. The trick with those is to use 0.05 as the trim relative error.
The latest Windows update 22H2 and the latest Unreal engine 5.2 are what I needed to get Nanite working.
With large meshes, Nanite doesn’t seem to reduce the mesh very much, and performance seems to be less than just using the mesh without Nanite.
Smaller meshes work reasonably well, so it saves a lot of time setting up the LODs
Maybe you need the DirectX 12 Ultimate with its Mesh Shading, to see performance gains at the hardware level.