I think it’s great that you are expanding on the Assets framework to make it more accessible — it certainly has some issues.
However, looking at your site (accessible-template.com) a quick browse of the home page shows me some key areas where it fails the WCAG AA compliance it claims to meet:
1. There are no focus styles on some links, including the logo and the hamburger menu on the right of the primary navigation. I do think it’s great the navigation styles are the same for hover and focus otherwise.
2. The footer links do not have any focus nor hover styles. There is no underline and outline is disabled. Restoring either one of those may be adequate.
3. The footer links also do not meet WCAG AA contrast requirements (#0099da text on #333333 background color is a 3.95:1 contrast ratio, which fails for body text).
I’m not trying to pick on you or your work (those three just jumped out at me immediately), but in my experience when you claim a product meets certain accessibility standards (or SEO standards, or validation standards, or whatever standards), people will look at your own site to see if it meets those same standards.