Holding Light sources for others

I cannot find any stipulation in the Light section that the holder of the source must be one of the people with full Light. Can they choose to assign themselves Dim and the full Light slot to others?

Taking that further, there isn’t even a stipulation that the carrier must be one of those with Dim Light. That strikes me as a stretch, outside of peculiar circumstances.

I’m comfortable allowing the GM to rely on common sense here.

If you crave dim light, perhaps get yourself a 10’ pole?

Yes, that occurred to me. Alternatively, use of a mirror in the other hand to direct light more purposefully.