We have an existing ephemeral PR environment with per-service GitHub deployment triggers. We want to pause automatic deployments for just that PR while keeping its environment and existing deployment intact.

1. If we update only branch via deploymentTriggerUpdate to a nonexistent holding branch, can a later GitHub pull_request.synchronize event recreate or reset those triggers or otherwise deploy the PR services?
2. Does omitting rootDirectory, repository, and checkSuites preserve their existing values, including any trigger-specific root-directory override?
3. Is there a supported reversible PR-environment-specific setting that stops all automatic PR deployments without deleting the environment or affecting other PRs, and without deploying services during the setting change?

Please do not ask us to post access tokens, environment variables, or secrets.