It doesn't matter if you develop or deploy or import a solution. Whatever you do will be done in your "Partner Space".
Think of it as a room for you as a partner, where nobody else has access but you.
In C4C, there is a customer room, where all partners meet and collaborate.
The question is who creates the rooms and who assigns the users to the different rooms. I know how it works technically, but I don't know who is doing it in the tenant lifecycle. I'll follow up on this.