Evaluate using a CDN / creating a "smart mirror"
The default mirror used by ex: archlinux-docker isn't fast for everyone (@lahwaacz can confirm).
Some of the big CDN players (ex: Cloudflare and Fastly) offers sponsorship for open-source project, maybe we should take advantage of it? We can either use it as a cache or setup a "smart mirror" which choose the closest mirror relative to the user (can be done with: CLoudflare Workers or Fastly Edge cloud platform)
https://cloudflaremirrors.com/ is also worth mentioning, it is very broken though (the files is sent without content-length and range requests isn't supported).
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information