I’m always interested in working with helpful collaborators like that.
I have been nudged toward a few things, but we have to look at whatever open license contract they have and how much work needs to be done. Did you have something in mind? Mythras?
Generally right now we are moving into the direction of making Codex it’s own thing, loosely based on OSR-ish OGL. I like the twenty sided dice for use with the roll-many / keep one system. I think it gives you a wide range of probability and is pretty easy to handle.
But that doesn’t mean other systems aren’t also interesting, I know many people have adapted Codex for many other systems.