Feature Request: The ability to Lock and/or Selectively bake lightmass on objects.

It would be really great to be able to on a per object basis, be able to Lock and object’s Lightmass map and exclude it from being recalculated. Where when you did the existing data would be reused/retained. Also the ability to lightmass a single or selected objects. Again This would reuse existing data for unselected objects.