Love the idea but no, for full transparency, I didn't have that in mind. I used this concept to test shade steps on a recent design system and all resulting shades ,used as a foreground or background color, were indeed tested in isolation for WCAG AA and that was all.

I was seeking for a bit of exploration and geek fun.. Its fair to say that all this arts and crafts could be solved in a 2 or 3 parts mathematical formula.. But you are absolutely right and relative contrast is a must and something worth to think about!