This is bordering on paranoia. If the bad sector contains a critical part of the filesystem, you're going to lose everything anyway.

Do modern disks even have physical "sectors" anymore? Isn't it all virtual?

Without dedup you're just going to backup less stuff, which is far worse.

> This is bordering on paranoia.

What? You actually think that the mere idea of a backup getting corrupted is something that is "bordering on paranoia"? Have you ever heard of redundancy or even RAID?

> If the bad sector contains a critical part of the filesystem, you're going to lose everything anyway.

Do you honestly failed to understand that the problem is actually the "lose everything" part?