The 'other solutions' were misrepresented during that presentation. You can clone a repo using a nostr url and interact PRs as branches. Just push a branch starting with `pr/` and it will be submitted as a PR. Any branch starting with the prefix on the remote is a open PR. The full commit id's are maintained.
But the original git folder along with the source must be committed to a centralized server if I'm not mistaken right? What was interesting about nestr was that it used blossom for that part? I maybe wrong this is just what my brain came up with trying to understand these solutions.
The content of each commit in a PR is sent via nostr relays. The commits from maintainers pushed to the `main` branch are just sent to the git servers listed in the announcement event. However, is really easy for maintainers to change the git servers that everyone pulls from. NIP-34 turns git servers into dumb data relays similar to nostr relays.