When using 'r.VT.SplitPhysicalPoolSize 64' with nanite meshes, mesh painting does not update in real time (only updates after stroke finished), duplicates mesh painting across separate instances of a mesh, and sometimes doesn't show up in PIE.

When using Mesh Painting on nanite meshes in 5.5 with 'r.VT.SplitPhysicalPoolSize' set to non-zero values (e.g. 16, 64), several issues occur, such as:
1. Painting doesn't update in real time (only updates after stroke finished)
2. Painting shows up on other mesh painted instances of a mesh, even if that mesh has its own, different mesh texture set in its details
3. Painting isn't visible in PIE (happens inconsistently)

When 'r.VT.SplitPhysicalPoolSize' is set to a value such as 158 or greater, the duplication of painting is resolved, as presumably this size allows all tiles to go into the same physical pool. The mesh painting system may also not be properly configured to work with the virtual texture pool system, but it's hard to say exactly what's going wrong.

1. Create a project with Virtual Textures enabled
2. Use the `r.VT.SplitPhysicalPoolSize` to allow the physical pool to split when it goes over the set value. (use a small value like 16 for ease of reproducibility)
3. Select mesh painting mode
4. Select a mesh and choose texture paint
5. Choose paint mode
6. Texture paint several copies of the same object
7. Notice errors when painting, and in PIE