I've got a similar setup, but use Kopia for backup which does all that you describe but also handles deduplication of data very well.
For example I've added older less structured backups to my "good" backup now and since there is a lot of duplication between a 4 year old backup and a 5 year old backup it barely increased the storage space usage.
yeah, there's a bunch of lessons that tend to only be learned the hard way, despite most guides mentioning them.
similarly to how RAID should not be treated as a backup.