CentOS 8 will go EOL on December 31, 2021. In order to prepare for the transition to CentOS Stream could you make a separate image available for testing Stream?
One can swap the existing CentOS 8 images over to Stream with dnf commands, but we use Equinix Metal as a platform for our CI, and running dnf to swap to stream will potentially require a reboot and add a lot of time to our deployments.