I was an early Beta tester for Elbie Mendenhall's Rite Angle angle-of-at-tack indicator, using our Glasair as a testbed. Nothing wrong with Elbie's product, but readers should know that finding a suitable location for the vane might not be easy.
Specifically, I mounted the vane about 6 inches below the wing, attached to streamlined tubing from an inspection panel. The data proved this location was still in the bow wave of the Glasair wing (we surmised) when approaching stall. The vane needed to be further away or more forward from the leading edge, but I didn't pursue it.
An early Glasair builder wrote about drilling holes in the leading edge of the wing for AOA data, a la Advanced Flight. While he claimed good success, it seems no one could duplicate his results. Some wings are very finicky and you may have to experiment with your installation to get valid readings.
Your angle of attack article was great but several shops pointed out that the devices all sound like major installations to them, requiring a 337 and that without an STC, I would be advised to not install one in my Mooney. I did find that two of the manufacturers have letters from two different FSDOs deeming the basic device, without any wiring, to be a minor install--no 337 required--but that was only from two offices.
One manufacturer, Alpha Systems, feels your article made the 337 issue sound less daunting than it is. I suspect I'm not the only reader running into this issue. Keep us informed what you might learn. I'd love to install an AoA.