I don't really understand stone evolutions to begin with other than to explain new gens giving old mons evolutions, but they just make new special snowflake items for those mons anyway. stone evolution should only be for the eevee line, make dawn -> espeon, froslass and gallade can just be gender dependent evolutions
dusk -> umbreon, everything else can just be levelup
shiny -> sylveon, everything else can just be levelup