A member who hosts a retreat at the house is not renting the house. They are temporarily taking on stewardship of a room that is older than their booking.
That framing matters. Rentals optimize for convenience. Covenants optimize for coherence. When you host under the charter, the house will make some things easy for you and some things difficult — and the difficult ones are the point.
Why members can host retreats at Galactic Lighthouse — and why that is not a rental.