Just typed a long reply and accidentally hit some keyboard combo that evidently equals the back button.
Anyway yes, I almost always belay directly from the harness. None of my partners fall on anything I lead anyway, but I could imagine for a guide it would be annoying having people hanging off your waist all day while you shout down, "use your feet ohh ya that's it you're a rock star you got it" all day long.
...one figure eight after pre-tension eliminates extension...
True--I didn't express my thoughts on that completely. Sometimes when you tie the figure eight powerpoint and move into belay position you realize you got it wrong. So you can either redo it or accept a slightly unequalized leg. This was part of my thoughts about time since with Goldstone's method it's very quick to adjust the clove.
The other thing you can do is just use two sliding x's instead of the figure eight powerpoint. But then you have the problem of either accepting possible extension or tying those limiter knots.
Also if you use cordalettes a lot you get better at getting your powerpoint knot correct the first time. I know I used to struggle with that damn thing all the time though before I gave up cordalettes.
Goldstone is a pretty well known Gunks guy and a math professor. He's done some work with theory regarding anchor safety and I believe some actually testing as well. I don't know him but have read some of his stuff online here and there. I believe his ideas are sound and well regarded by the climbing community.