I'm back! Thanks Funkymunky, that did in fact help. I ended up understanding it, but before I sat down to rewrite some things,
I discovered that I would eventually have to deal with a patented approach, a Geoclipmaps apparently is.
So I went back to sort of a compromise. I do classic LOD chunks now, but baked into a single mesh, where every verex has its fp LOD value set as one of its attributes.
The cool thing about this is that i can use euclidean distances rather than manhattan or chessboard distances, and that I get a seamless result, as I lerp the LOD values downward towards the next chunk (which requires it's sample LOD to match its mesh density or be coarser.)
I now have
standardlod.png 244.54KB 0 downloads
... And I'm now at the point where I'm actually considering applying a modulo equal to the highest density -quads, rather than using modulo of a chunk size. (here, the chunk size is constant, only the density changes)
This causes obvious but smooth vertex scaling in the distance, which I actually like. Viewing with the wireframe on also makes it more obvious.
I think I've managed to do a fair settlement, but you're welcome to input on the approach, of course!