Multihome - how does device licensing work?

If I create/own multiple locations, how are device licenses/subscriptions counted? Does each location have the same number of devices available or are licenses summed across all the locations I own?

I would assume that if I am "invited" to another location, I would inherit that location's device limits per the existing license of that location's owner?

For your locations (you are the Owner in your Simple Control account), device counts are summed across all locations you own.

When you grant permission to a particular location to some other Simple Control account whether as an Admin or Guest, that Admin/Guest is treated as if they are on your account for the duration of the time they are controlling that location. They don't need their own licenses. However, if you grant Admin access specifically, they will need a Multihome or System license. A Guest genuinely needs no license. They could get the System app, have access granted by you, and have free Guest (no editing) access to your config.

Thank you.