enable artists running Lightning nodes to register that node with the site and receive Lightning payments directly to their node from fans

Did you consider that you originally had the correct model, but your customers should have been record labels instead of individual artists?

It seems to me that there is still a role for record labels to play, and much like Galoy and “community custody”, that could be it.

Yes, labels and syndicates have always been a consideration and continue to be. I think the best solution is one that gives both individuals and teams the tools they need to distribute content and earn payments easily.