This is the closest I've found.
https://www.rainierarms.com/f-1-firearms-miculek-handguard-15
That ALG is pretty dang close to round. Why such dislike for "just slightly not round?"
That Miculek HG looks great, but it's pretty dang expensive
I'm going to have a KX5 flash can pinned and welded on a 14.5" barrel, and the 15" HG would extend slightly over the can. Anything less than round wouldn't look quite as cool as a completely round HG, in MHO. The NC-1 HG would work, but I'm hoping to find something with a smaller ID so the can isn't as visually dwarfed.
White, I have a 15.5" NC-1 HG mounted on a 16" barrel with a Ferfrans CRD brake, and have the HG covering the rear edge of the brake shroud. I have yet to complete the build, but the upper looks way cool!
GOML, the JP HG has the same inner and outer diameters as the NC-1, so it's interesting you'd think it feels more slender. It does look pretty nice, though.
As it is so far, I will likely go with the ALG V2, even though it's not quite round. It doesn't have a rail all along its length, which I like. It'll also be a new experience for me, which tips the scales further in its favor. Not too pricey, either.
Thanks for all the input, folks!