We approach it a bit different: we blur the lines between E2E testing and production monitoring. You run an E2E test and promote it to a monitor that runs around the clock.
It's quite powerful. Just an E2E test that logs into your production environment after deploy and then every 10 minutes will catch a ton of catastrophic bugs.
You can also trigger them in CI or right after production deployment.
Big fat disclaimer: I'm a founder and CTO.