Does any openSUSE flavor support / on a filesystem type that does not support immutable flag? A service could be employed that checks for non-zero sizes on repo*.repo files in /etc/zypp/repos.d/ and restores the empties. Or, do as I was doing:
# cat /usr/local/bin/zup
#!/bin/bash
[ -s /etc/zypp/repo*.repo ] && rm /etc/zypp/repos.d/repo*.repo 2> /dev/null
echo 'time zypper -v up'
time zypper -v up
[ -s /etc/zypp/repo*.repo ] && rm /etc/zypp/repos.d/repo*.repo 2> /dev/null
# cat /usr/local/bin/zref
#!/bin/bash
[ -s /etc/zypp/repo*.repo ] && rm /etc/zypp/repos.d/repo*.repo 2> /dev/null
echo 'zypper ref'
zypper ref
[ -s /etc/zypp/repo*.repo ] && rm /etc/zypp/repos.d/repo*.repo 2> /dev/null
#