It’s not a good thought. Run a single client (uptime kuma) and ask it to alert you on expiration proximity. I.e. implement proper monitoring and alerting. No need to randomly degrade your users’ experience and hope they’ll notify you instead of shrugging and going to a site that doesn’t throw made-up http errors at them randomly.

If a “canary” is degrading users, it’s misdesigned.

The canary narrows the blast radius and time-to-detection.