I just upgraded Copr instance to new version.
There is one big change. You can now lower priority of your build.
It was introduced to easy rebuild of rubygems and pypi. But it can be
used by CI systems later.
Copr-cli from our git, has --background option already. It lowers the
priority. But due compatibility reason we will not push the package into
main Fedora and we will wait one or two weeks.
If you want to give it try, then you can install it from our copr project.