Same as wlays.
Don’t use the landacape for things that need detail - in fact, don’t use the landacape at all.
Nanite replaces it anyway. Use static meshes instead.
Or, if you want to waste your life on something that will never work right, use landacapes with RTV; use the combined output of meshes + landacape to render some mixed but half decent looking stuff with somewhat scalable resolution…
Possibly onto a heightfield mesh instead of a landscape…