I found this on Novak's website while looking at some other parts.
They are offering a 4.31:1 first gear for the AX15.
https://www.novak-adapt.com/forum/d/56-new-product-ax15-4311-low-first-gear-conversion
https://www.novak-adapt.com/catalog/transmission/transmission-parts/ax15-low-first-gear.html
Probably not worth it to most at $530, but it is good to see more parts becoming available.