I'm fairly new, but there is only 1 reasonable solution. Allow for an infinite amount of instanced houses. How they handle the Wards is up to them. Randomize the names or just number them. Duplicate maps. It doesn't matter. 1 house per account, houses are account wide. FC houses can keep the current rules. It's not that complicated to decide what to do. I don't know about the programming or the server requirements.

If it's not doable, then remove the feature altogether. Everyone pays, everyone has a right to it the feature. I don't know how they do things in Japan, but in North America we don't bring enough cupcakes for only half the party. This is grade school shit.

Thanks