Good Read, Roger!
A couple things popped out at me.
You wrote:
"…The vortex burner is epitomised by the MSR XGK stove, which makes a very loud noise. In the vortex design the fuel comes out of a jet into a semi-enclosed volume and hits a baffle plate: the round dish in the middle supported by glowing wires. While doing this it drags air into the fuel stream from the inlets around the bottom so it can burn, but the flow is unstable. The unstable flow and the design of the burner create a vortex of air that oscillates like mad, and the very loud roar of the stove is due to this chaotic vortex oscillation."
and
"…Okay, there is no obvious sidewall and no obvious splash plate as are found in a typical vortex burner such as is shown in the forth photo for instance. But wait a moment – the base of the pot can function as a splash plate, and the air rushing inwards can act as a soft sidewall. You can't see the flames making a full ring as the combustion has almost completed when only halfway around the loop. But there is an inrush of air at the level of the burner head. So what happens when you take the pot off, as in the previous photo? The shape of the flame changes a bit – it sticks up a lot more, and so does the sound. Yep, the pot is shaping the flame like a splash plate."
I would submit that the "roar" is not necessary. Carefull tuning of the plate on the roarer style burners will significanly reduce the sound. Indeed, after running for a minute or so, I turn my stove down to the point of just hissing…no roar at all. This is simply a byproduct of the "bell" design. It is, in effect, overloading the mixing chanber then repeating…
The holes on the 300t are simply to facilitate lighting. No mixing means a no combustion. Or, sooty orange flames. Try it by taping off the vents, easy to see.
Ahh, as far as reducing weight, removing the flame spreader certanly helps. Along with all the fancy brass nuts, et all. A screw on stem would double as a lock for the jet. But, as you say, the benefits of an extra few grams is hardly worth it.
Minor points on an otherwise good article.
Other low pressure gas mixes should be examined before trying to come up with a standard. For example, acetylene can be disolved in isobutane at relativly low pressures, too, and has significantly higher heat.
