Awesome work! I was wanting to build a library like this myself but you've executed it way better! You should try to build and charge for a web API for this to let communities auto-generate avatars for their new users.
That sounds a great side project, since some developers might prefer a static svg dynamically created via url like boringavatar.app/[username here].
There's some prior work on this: e.g. https://github.com/lfades/static-tweet and https://github.com/vercel/og-image.