I already gave you MY solution. I'd not sit there and figure out a smart semi automatic solution for days. I'd just do it. By hand I am personally not using Unwrap Pro. I maybe should give it a go. But this is a company internal guide, not everything in there is done by me personally.
I'm looking though the Metal Gear Solid assets to see how things were done back in the day and I can't figure out how the texture shading is done. The texture fades to black along the bottom of the ceiling rock where it meets the wall: But I can't see how this is achieved. It's not a different texture: it doesn't seem to…