When trying to distribute an item with versions for both classic and PBR systems, a buyer with 1.5 only will not be able to purchase. This necessitates making two packs instead of one across a whole product line. As a content creator, I would rather have one store item for any set, and the included textures for both the new and older systems. If I have to choose, I'll go with PBR only and not make a legacy item, but I'd rather offer both.

I'm arguing for this being a bug because it is not an elegant solution and will affect many developers, potentially costing Marketplace business and limiting the offerings to customers.