OK, you are doing what I thought, then, controlling the water temp in the HLT, not really the wort. And yes, constantly moving the wort through that would certainly eventually equalize. I already had the strike temperature thing figured out. You'll still have the heat losses in the hoses, etc, but they're made up for by running the wort through the hot water continuously.
Took a minute, but yep, I got ya. That's a guaranteed no-scorch way to do it, too. Anytime you're applying extreme heat directly to the wort, there's a scorch risk. I get it. I could do the same with two kettles, using the boil kettle first as HLT, then draining it when it's time to boil, but I think I'd be just as happy with a PWM/PID on a heat source under one kettle for mash temperature control. No plastic on the hot side that way. I'm not a fan of plastic in a hot process. Dunno why and can't explain it, but I just don't like it. That's the one step (putting the wort in a holding bucket before boil) that I REALLY want to eliminate. I think I'd much rather keep it warm while I'm sparging. Again, I have no answer for that way of thinking, other than it just seems like the right thing to do. Can't do that in a plastic bucket.
My only point is that its not energy efficient to heat water to heat something else. Does it produce a higher quality product? Probably, otherwise why would the Big Boys do it that way (with steam rather than hot water)? There's too much energy loss in heat exchangers and piping if the goal is to reduce the energy costs. Thermodynamics explained that to me back in the early 80's. IIRC, Alan's original post was about reducing his energy cost in his brewing. I don't think what he has drawn there is gonna do it. I tagged on to it because it's the opposite of what I'm thinking about doing, going gas to electric. Electric is certainly a lot more controllable where you need a lot of control.