It would be useful to add an optional stream: key to the data.configurations section of the Packager v3 format. This would allow us to submit the module with a custom stream name for certain contexts.

As a real-world example, I currently maintain a variant of the 16 stream for EPEL 9 called 16-epel which is needed because the RHEL module does not provide v8-devel, needed for some EPEL packages. Right now, I have to maintain a completely separate branch in dist-git, despite the modulemd being essentially identical except for the stream name. It would be much more convenient to have an override in the configurations section instead.