Forums mostly focus on redirection from www to non-www and not the other way around (redirecting from non-www to www) so I wrote a blog post explaining how I do it using docker labels with Traefik v2. Please give this topic a heart if you find this helpful and those using other methods besides Docker please feel free to share your implementations below. Thanks!
Really nice, I used this as my foundation for my own implementation because I agree with your sentiment, but instead of going HTTP to HTTPS I want to go HTTPS to HTTP (static pages not needing certificates) and I can in no way possible get that to work. The rest of it, non-www to www is totally fine, though.