See https://github.com/googleapis/google-cloud-php/blob/b89abc7cd62cc436ecfd23b3e1b5825bbd16147e/release-notes.md

I used BEGIN_COMMIT_OVERRIDE for a PR which contains 40 different conventional commit lines. Now, each single line is repeated 40 times in the release notes (resulting in 1600 lines of conventional commits!).

PR with BEGIN_COMMIT_OVERRIDE: googleapis/google-cloud-php#8424

Screenshot: