I think a nice way to give us extra content is to let us quest to increase retainer inventory by caps of 50 or 100 at a time. 5 or 10 Quests of increasing difficulty or bigger timesink even (by collecting items, like the moat carps for the fishingrod in ff11). Please consider this. Most of the dedicated crafters are already craving more retainer inventory slots. But just handing it to us without having to put in any work is also not what we need in this game.