Irrelevant question, but why don't you want to have the repos in your own account?

To me sets with canonical names are an antipattern (see discussion in https://github.com/nostr-protocol/nips/pull/880 and the trouble we all had to prune the spec from these). I think the concept of "starred" is just publishing a reaction to a repository (with a "k" tag of "30617"). Those can easily be queried later. Following should be a simple list, either if you want to follow a repository to see everything that happens in it or someone to see their repositories and the patches they send elsewhere. That should be the base and the simplest thing to implement. Sets are much more complex. Organizing people and repositories in sets can be done (like for all the other lists we also have sets) but honestly that's more like a power user feature and we should postpone that to 2027 because there aren't even enough repositories today to fill a short simple list.