1024px/meter on an environment rock is pretty nuts imho. Is it a hero asset? You could use UDIMs, but I would suggest to go with a single 4k map and bump the visual res with moss decals and painting small foliage on top.
Ahh you are not talking about a specific mesh. My bad! There is a technique known as Megatextures, for example in Rage, but I don't think anyone uses this technique anymore. Nowadays, a combination of different techniques is usually used. For example this structure is 70 x 50 x 18 meters and uses custom vertex normals on…