Actually, you missed some things, Daemon. Paint the model a flourescent color. Equip the model and file before departure so separation other than VFR methods can be used. Don't let anyone, regardless of size, divert from the planned route, filed or not, regardless of reason, so they won't be away from published Victor airways, waypoints of any kind or other known locations. Don't know what to suggest about some of the ideas upcoming in the near future such as GPS direct (actually already routine in some places) or the satellite-based traffic separation systems, allowing routing/route deviations for whatever reason, based on current, real-time known traffic loading. Anywhere.
This has been fun and educational but I feel I should add, this coming from my five-year involvement as a part of the Experimental Department with a well-known GA manufacturer in research, development and certification: Remember the FAA will ask you, not to prove or to example or to show them anything. They will ask you to demonstrate
to them why this or that is a good idea so it can be acceptable to the Administrator. If it's OK to quote another thread where I posted it, it will be much better to offer the FAA an idea in lieu of a rebuttal about how to handle this.
To drop from the flight levels to model levels, if there is an incident/accident involving a BLOS model in the meantime, especially if it involves a fatality, I would expect the FAA, if not the general public's uninformed response to be "That's all, folks", and lump all models operated in any way under the steamroller.
Maybe it's time to invest in an indoor micro/flyable airplane, just in case