Real simple suggestion: please make luminous plaster backwalls emit their own light. (Quite frankly, I don’t know why this isn’t a feature to begin with.)
Backwalls made from illuminating blocks (plaster and gems) should be differentiated from regular plaster or non-light emitting block backwalls.
Allowing backwalls to illuminate would allow builders to create art and spaces that truly don’t need extra lights. As it stands now… you still need to add supplemental lighting for backwalls on these builds because otherwise you get black spots.