question regarding backup via ZFS snapshot replication and deleting old GitLab backups

I hope it is okay and helpful also for others
to use GitHub Issues to discuss two GitLab admin questions.

According to the following lines in docker-compose.yml

   volumes:
      - gitlab-data:/home/git/data:Z

the GitLab data is kept in
/var/lib/docker/volumes/docker-compose_gitlab-data/_data.
All filesystems are on ZFS, and (atomic) snapshots are made and replicated to another machine every day.
Because of this, I disabled the GitLab backup feature in docker-compose.yml

     - GITLAB_BACKUP_SCHEDULE=disable

Is this a safe backup strategy for GitLab?

There are still two old backups (tar files) remaining under
/var/lib/docker/volumes/docker-compose_gitlab-data/_data/backups/
taking up quite some space.
Is it safe to manually delete these files?

Start with the backup-related entries in docker-compose.yml and the tar files under /var/lib/docker/volumes/docker-compose_gitlab-data/_data/backups/. Review how ZFS snapshots and replication relate to GitLab's backup feature, then document whether this strategy is safe and whether the old backup files can be deleted.