Maintenance mode rewrites hundreds of bad sectors

[xyz321]

Interestingly, your test log shows that selective tests are being used but obviously not quickly enough and I haven't read through that part of fix-disk to see how it uses selective tests (xyz321 can you provide any insight?)

As far as I remember when fix-disk finds and repairs a faulty sector, it will then use a selective test to scan the remainder of the disk instead of scanning the whole disk again.