How to deal with sysusers files inside the package

I'm looking at converting my package (where I'm also the upstream) to use sysusers.d but I'd prefer shipping the sysusers.d file inside the source tarball rather than in packaging. This allows me to use the same definition on Debian, which I think is a huge benefit of systemd standardizing these kinds of things. The documentation[1] only mentions shipping it as a separate source, not inside the tarball. Should I simply replace %{SOURCE3} in the docs with the path from the extracted tarball? If so, is this something that the packaging-guidelines should document? I also noticed that %sysusers_create_compat isn't in EL8 and I'd rather not depend on epel-rpm-macros. Today we build completely outside of EPEL and I'd prefer to keep it that way. Is the recommended way to use %sysusers_create_package (provided by systemd-rpm-macros) instead? [1]: https://docs.fedoraproject.org/en-US/packaging-guidelines/UsersAndGroups/