Thanks Kris, I had thought that was what you were talking about. I remember on the way to Stoyoma we had talked about the grid.
That would be a challenge for sure. It sounds neat, but would it be allowed? As all cachers are not able to place 5/5 caches and therefore wouldn't be able to go for your cache? I know of a specific rule when hosting an event, but am not sure of one for caches.
The idea is really neat and for sure sounds like fun.