Ok, I found one of our repos has a GHA version that doesn't do any gymnastics. Unfortunately, it's one of our private repos, so I apologize for the wall of incoming code!
We also adopted Pulumi for all of our projects and are using GitHub Actions as a CI/CD platform. I'm talking about some 30 repositories ranging from simple ones to those needing a little bit more orchestration (e.g. creating Lambda deployment packages, multiarch Docker image builds or interleaving Pulumi provisioning with building applications on the runner). So far we haven't encountered anything that wouldn't be solved and are more than happy.