Shared estates

How many shared estates can you belong to? I know you can share your own with up to 3 people, but how many houses can I be shared at?

I've only been able to attach to two at a time. Kind of a low limit.

I want to say three is the limit, maybe four. I hit the limit once and had to leave one to be attached to another.

You can only be on a maximum of two shared estates per character.

Can confirm 2. I wish the would up the limit for this and for how many you can share your own with.