Got an idea for secrets bases. They sort of work like vips, where there's a big hall with rooms. Secret base entrances on map, such as trees, bushes, and dents will have warp sign that will warp you to the front of a room in the hall. There'll be six halls, one for each different base layout. As to whether or not they'll be donor only or sold as houses, I have no idea. Got one hall and one room done.
If you want to see the room, go under the 1x1 glowstone tower behind the Rusturf Tunnel exterior.