

(It’s a joke/reference, I guess it’s not 100% known though. My bad.)
I really do hate “I know what I have so you are going to pay whatever number I set” capitalism though, which is what they do here. These registrars figured out a loophole around the redemption grace period and are, from the start, set up to make you lose the domain and then spend significant money on a completely unfair auction where they have the power to plant fake bids, rather than paying the usual static redemption fees that aren’t that excessive.
Borg or the like with ‘hardcoded’ plaintext/regularly full-disk-encrypted key is acceptable. Someone that has your unencrypted private key sitting on your server has almost certainly already obtained access to the entire set of data you’re backing up, with the backup key itself only meaningfully guarding access to older backups.
The more important thing is to securely keep extra copies in case the server fails. I keep mine in a group in my password manager, one per repo.