So it turns out that it just took ages. I ran it twice (both did 10% for ages then went up to ~90% and finished), but the drive was still not fixed. I set Reflect to ignore those bad blocks and I have a backup. Now I need to figure out how to get it on the new laptop as the partition size is ~1TB but the laptop only has ~500GB. I would appreciate this thread being closed as this is no longer an issue.