This is the (basically) finished painting. I have a couple bits of touchup to get back to once it dries up a bit better, but substantially its finished. I was wrestling with how to handle the background area, and after an aborted go at tinting the grid squares I settled on scraping the whole thing over with titanium white using a flexible palette knife.
The result is the pencil grid remains visible if ghostly, just as it is under some of the yellow internal areas, and the graphite is fixed in place now without needing an additional varnish coat or whatnot just to avoid future smearing.
I have been liking, and trying to play around in little ways with, the idea of making a painting be a record of the process of how it was made, and trying to preserve the pencil prep work here is in that vein.
I've got another similar idea to execute, with a Sierpinski pyramid on a similar square-yard canvas, where I think I'll take a different tack on laying out pencil guidelines but try to keep the overall process and process-as-aesthetic thing going.