It has been shown recently that there is a pressing need for shared claims. Making steel is simply too big a chore for one person, and a shared claim would allow multiple people to work on it with relative safety.
However, some people may wish to have private property as well as shared property. Sharing your claims globally would impede this. So, I propose that in the menu one gets when right-clicking on the claim pole, there is an add/remove persons allowed button that affects that claim only (type in name or select from kinlist - select all option required). So you could share the communal crucible with everyone in your village, your garden with just a couple of friends, your temporary fur drying post with a fellow hunter you randomly ran into, and your cabin with nobody else.