Now that there is no longer an Alternate Lower Start, I'd like to suggest that some Lower-themed vanity outfits make their way into Upper's cabinet to emphasize the influx of grimy refugees from below. I'm sure the dungeon masters know better than I do what garments would be appropriate, but I imagine the likes of gang colors, cult mementos, and slime-bitten rags.
Or perhaps the option to start in the Crone could also be restored under a different model, dropping players off in the Housing Vault or the flooded ruins...