Notice: regardless of which version you select, you'll be able to use the same add-on for all our themes (we include all available versions in each purchase, regardless of which theme you select). The only reason why we're making you choose the edition below is to ensure that the add-on is compatible with theme you selected.
i.e John purchases the "for Elixir" version of the add-on, but he also has Ethereal. He will be able to use that add-on for both Elixir and Ethereal. He doesn't have to buy the "for Ethereal" one separately to use it for Ethereal.