How to build a package that updates an OS config file, 11.3 vs 11.4

At installation time, I install several packages that update /etc/profile, /etc/syslog.conf

The updates are delivered by an "overlay" line in the packages' manifest.

This worked fine on 11.3 - but broke one 11.4 was released, because the ownership of the system files changed. For example, syslog.conf is owned by the 'sys' group on 11.3, but by the 'root' group on 11.4.

This is a small part of the package - the rest of the packages' updates work correctly on both 11.3 and 11.4

How do I update my package to update both 11.3 and 11.4?