I am curious about composes.centos.org and it's intended use case or guidance on what it should/can be used for.  If it is reasonable, I would like to try to write a dnf plugin to simplify using it for package rollbacks.  Is someone else already working on this?  Is there a better way to go about doing this?

Ultimately, I would like it so when submitting a bug about a regression, it is easy for the user to specify between what compose dates the regression first appeared.