Repost from 3.7, it is still unchanged in 3.8. The Arena Commander is an easy way for initial trying out and testing ships and loadouts, before you take them into the PU. But currently, I think since 3.4, you only can modify ships for the AC you bought with real money / store credits. Ships bought with aUEC are excluded from the AC ship selection too, ships that are RECed can't be modified. This excludes a lot of people from taking more advanced loadouts into the AC if they can't or won't invest money. For example, there was a 1vs1 tournament, but a lot of player couldn't participate with a competitive loadout without using real money / store credits. https://starcitizencompetitivecombatclub.challonge.com/de/sc37_1v1