Tier 1 Weapons on Later Ships?

It seems like you are unable to place tier 1 weapon modules onto ships once you have reached Era 2 and so on, this seems counter-productive as a tactic that is can be effective is to keep tier 1 weapons on new ship designs in order to churn out a lot of cheap ships quickly.  This horde tactic benefited greatly from the ability to pick lower level weapons, which was allowed in Endless Legend, you could just press a button to make the older tier stuff appear or disappear.  Am I just blind and missing that button?