Hard Disk Monitoring

I have a Seagate 8TB HDD, which shows 3% Health, though Surface scan has shown only one bad sector. Can I use this disk, instead of scrapping, use as the shelf-back up (3-2-1) system, with the new healthy one as the active one connected to desktop ?

In general, we can't expect too much from a hard disk with as low health as 3%.

For secondary storage (for not critical data) yes, it may be still acceptable and may work - but generally you can expect data corruption / data loss.