I would suggest adding the ability to auth via a magic-link in your web app. This would allow your tests to bypass the auth flow entirely by passing an auth token as a request parameter in the first URL of your test. You can pass new auth tokens when you go to run your tests either via the UI or via our API if you have it hooked up to your CI/CD pipeline. More docs on how to do it via the API is here - we call these 'request overrides' in our docs: https://reflect.run/docs/developer-api/documentation/#run-te....
In terms of added security, some options there would be to only enable these "magic links" in staging and only enable this type of auth for a least-privledged user account (e.g. no admin or employee accounts could auth this way).