I think it's beimg discussed as a stopgap solution, much like using --enforce-dns-checkpoints, which would just use the dns system instead of another chain.
Personally I say, stick with DNS for the half-assed patch, spend the resources on long-term solutions.
Rsync is the correct solution. It does exactly what you want and nothing more. A script that uses rsync is future-proof. Other backup solutions depend on the maintenance of the software, which could be abandoned, go up in price, or have vulnerabilities.
Hate to be the guy that says "why don't you just do
<different setup>
?" But unless you are on solar, I wouldn't worry about power consumption. Jellyfin is a resource-intensive program and you'll have a better experience with a dedicated graphics card (as recommended in the docs). I also recommend SATA or PCIe storage I/O instead of USB.
Well having the wrong permissions in system files will mess up your system. So when you restore from backup and want the backed-up permissions too.