I emailed the “guys” and told them I thought they were missing the opportunity to include 60m in the same antenna. I did the math and based on rough calculations I determined approx where they should tap the coil a second time to be centered on channel 3.
Ken tested it out and found it matched well on 60m, although not quite where I thought it would be (in my defense I didn’t have the coil form dimensions or a mock up in-front of me).
If you look online the antenna is now advertised as 80/60m and the instructions include the 60m tap location. I think its pretty neat that the company puts out in development products so we get to see what’s cooking before it comes out. In this case a suggestion made it into the final product before it ever got sold
I will likely have different tap locations on my example as I use a 20’ pole, not a 17’ pole that the antenna is designed for. Since I have the real estate I will be adding 1.5 feet to either side of the coil. That 120% of the original design’s vertical radiator, so slightly better efficiency on both bands.