I've asked these same questions to both division and region staff members, and the answer Don is providing is what I consistently receive in response. While I still have some questions about the validity of the position given the supremacy clause in GRP, I have accepted it and am working on an initiative with other VATUSA facilities in order to remain in alignment with their position: Automatic visiting controller status. I believe this allows like-minded facilities to participate together as they wish without impacting others, while still playing within the bounds of all of the rules as interpreted. The initiative has generally received positive feedback, even from those who aren't interested in direct participation.
We (ZHU) have agreements in place with two neighboring facilities at this time and have inquiries out to other facilities. We've only received one flat-out no, and a few others are currently being discussed. Some facilities have concerns, but I do feel that they can all be addressed and the associated risks mitigated. I take the position that we're here to have fun, and allowing controllers to float to wherever they can have the most fun and be best used benefits everybody and helps the activity of all facilities, the division, and VATSIM as a whole. I sincerely think that we can do something good for all pilots and controllers on the network, even if it takes some out-of-the-box thinking.
If there are any other facilities interested in such an agreement with ZHU, feel free to drop me an email! Or do something similar with your neighboring facilities! It doesn't have to be with us! Our most recent language can be seen in the ZHU/ZME LOA. The highlights are: Automatic mutual visiting status, does not include designated airspace, no minimum activity requirements, and individual controllers can be excluded from the program, as required.