Doubling the inventory is urgently needed in Final Fantasy 14! This allows you to keep materials for multiple recipes that are running particularly often. Relief would also bring automatic taking of materials from inventory of assistants when executing recipes. Everything else leads to awkward moving of materials between inventory, assistant and chocobo bag. Likewise circumstances caused by the sale and repurchase of materials. We play Final Fantasy and no accounting in managing insufficient disk space.
I always clear out materials before every major expansion. Help from the program would be helpful here. It requires expert knowledge of the purpose for which objects exist. A lot of stuff comes from older content where few care anymore about the rewards that come with it. It takes some experience to assess which things are valuable and should not be deleted or sold. Newcomers in particular cannot assess this and keep everything possible as a precaution.