Since we only need to know the last compliance check I made a script to clean up all the previous reports before the next compliance check runs.

#!/bin/bash
#this script removes all the arf reports from the satellite server
###

#settings
USER=ronly
PASS=xxxxxxxxxxx
URI=https://localhost

#check amount of reports
while [ $(curl -k -u $USER:$PASS $URI/api/v2/compliance/arf_reports/ | python -m json.tool | grep \"\total\": | cut -f2 -d":" | cut -f1 -d"," | sed "s/ //g") -gt 0 ]; do
        #fetch reports
        for i in $(curl -k -u $USER:$PASS $URI/api/v2/compliance/arf_reports/ | python -m json.tool | grep \"\id\": | cut -f2 -d":" | cut -f1 -d"," | sed "s/ //g")
        #delete reports
        do
                curl -k -u $USER:$PASS -i -H "Content-Type: application/json" -X DELETE $URI/api/v2/compliance/arf_reports/$i
        done
done

To manually rerun the benchmark on all machines I use following ansible command

ansible all -m shell -a 'eval $(grep foreman_scap_client /var/spool/cron/root | cut -f6-7 -d" " | sed '/^$/d')'

 Update: Red Hat published my script https://access.redhat.com/solutions/3040861

 Update: After Satellite 6.3 the location for the cron rule has changed to /etc/cron.d/foreman_scap_client_cron