I had a similarly inspired idea recently but more deeply git/vcs-based https://github.com/MichaelBelousov/forkage, which would use arbitrary git providers for a registry and encourages editing your dependency's content but then you can promote your edits to a fork and search/diff other forks of packages.

fyi there's about 0 progress in that repo besides the README laying out the hypothetical CLI and file structure.