Most projects are parameterized at least with regards to sensitive config data, like credentials or dotenv files. These need to be stored somewhere, but not in git. They also need to be available when running previews or onStart scripts. IDX could either integrate with Secret Manager or allow its own config store (compare Gitpod's repo specific env vars: https://www.gitpod.io/docs/configure/repositories/environment-variables#environment-variables).