For dnf-nightly it would be nice to configure to store only 2-3 latest build (not the 14 days old builds) as those can be broken and we have to delete them manually. Would be nice to get UI where you can choose how many days/versions you want to keep.
I believe this was resolved via: https://pagure.io/copr/copr/issue/614 If you really need to have prunerepo run more often (ie. the issue 614 did not help), please reopen.