We had upgrade modules that works just fine and now we have unstable cores which does basically the same but now require more grind to upgrade just once and they also have expiry date compared to upgrade modules that are permanent. And to make things more questionable, upgrade modules are still in the game so what's the logic here? Why bloat the game with unnecessary things that are just temporary? Just to ensure everyone does the grind from scratch after a time period? Just a hamster wheel that goes nowhere?