When a pull request pushes your app past a size threshold, Tuist fails the tuist/bundle-size check run and puts an Accept button on it, so an increase you meant to make does not need a second commit to get through. Until now anyone with write access to the repository could press it, which is a wide door for a check whose job is to stop the merge.
Settings > Bundles now carries an Approvals policy.
Learn more in the bundle size documentation.