Thank you! Indeed it is pretty "hacky". Especially SEO-wise this is not really optimal. But as long as GItHub does not offer a native solution, it's the best you can get.
Btw... I just published my next article: https://markus-kottlaender.medium.com/when-youre-working-on-a-static-site-and-github-pages-feels-like-the-perfect-hosting-solution-a41c37f4e326
Will repost that here in a bit.
RE: GitHub Pages with Dynamic Routes