Support to have a light to influence only a few objects.
- To Do
Isn't this more commonly referred to as Light Linking in other applications? That is, the ability to associate lights with specific objects to illuminate? Light Groups are also a thing in some applications (Revit as one example) but AFAIK this refers simply to grouping multiple lights together in order to affect them as a combined set. Applications that support Light Linking generally let you associate either individual lights or groups of lights with one or more objects to illuminate.
Also for reference here's the one outstanding diff for Light Linking I could find which I believe is one of Tangent Animation's early mods that they submitted a few years ago: https://developer.blender.org/D1985