Function sync_boards 

pub async fn sync_boards(
    mirror: &Mirror,
    client: &GitHubClient,
    references: &BTreeSet<BoardRef>,
    force: bool,
) -> SyncReport

Bring the boards current, and nothing else: who the token is, every owner’s board list, then the cards of the referenced boards and of every board whose cards are held.

What a refresh of the boards page asks for. The whole pass also asks about every repository of every project, which is minutes of requests a person looking at a board is not waiting for. Nothing is forgotten here; that is the whole pass’s, which knows everything that is wanted.