I think I'm going to make a tentative fav group for "traditional_halo" at the end of this week unless any new posts come up that sway me. Maybe someone else wouldnt mind doing one for nontraditional. I've I think the solution here is both tags should exist.
We all (mostly) agree on what these are so the best solution is fav groups.
Also I dont think the BURs in OP are good since materials can come in various shapes. Let's swap them out for stuff like triangle_halo and whatnot but leave stuff like mechanical_halo unimplied.