I see the attic and bank spaces as being a commodity with diminishing returns. If you have only one 'home' and one wizard, you have a way of storing up to 300 items for later use. If you make another wizard and that wizard only has one 'home', then, per wizard, you can have store up to '250 items' per wizard. (True, could have 300 on one and only 200 on another, the idea is an average, so please don't misunderstand my point.)
Per wizard, when you buy another home, that attic space is shared among your homes including the dorm. Have just the dorm? The your attic holds 100 items per home. Have a dorm and another home (house/castle/whatever)? Then it's an average of 50 items per home. Have five homes (including your dorm of course)? Then that's 20 items per home.
I know that you can use an elixir to increase the storage of your home (inside or outside) by 50, but what about your attic? To me it would make sense for an attic to be per house and not per wizard. If not, then why not increase it for each house the person owns, with a way to increase it further by purchasing an elixir? Start with 100, then add 50 per house (and remove that extra 50 if a house is removed), with the option of using an elixir to further expand it.
For the shared bank, what about a way to increase that as well with an elixir? I'm sure some people get around this by creating a storage wizard and then only get on that wizard to swap stuff around. But if there was a way to increase that limit with an elixir, or better yet, have 50 storage per wizard on the account (so the shared bank would have 200 if the account has four wizards on it), then that would be a very welcome change.
On a related idea, a furniture item that could be used as an additional bank, but would be treated separately. Could place it anywhere in the home and anyone could interact with it (though anyone aside from the owner would be told that only the owner can open it). It could be placed in the shared bank, but only if it's empty and the amount that new bank could hold would be based on the size - tiny (10), small (25), medium (50), large (75), huge (100).
I'm sure I'm not the only one who would be very thankful for this improvement.
