I could add an early game-mid game building to spawn tier 1 and tier 2 spoils, while leaving the tier 3 spoils for the end-game. I could also add a new UI to have a general overview of the gatherers to quickly unassign them, keep track of the upgradable buildings and more. Something like a "Work" button on the top of the screen along the Relics and Boons buttons.
Thanks a lot for the feedback!