pr_overlap --branch merged every open pull request against main, although a pull request can only appear in the report when it shares a file or an export with the branch, so on a repository with a thousand open pull requests the check did not finish in an hour. probe lists each pull request's files and exports from git diff base...head, without a merge, and scan_all merges only the ones that overlap the branch; the others get empty sets, which is what they would contribute to the report. --out is unchanged.