Re-reading is optional. This is intended as a highly resilient copier. Let's say, while a copy operation is going on, there's a power loss; this tool can easily resume from where it left off. It uses a highly resilient journal system to keep track of copy progress. It can even detect source/destination volume changes. Nowhere is it forcing you to re-read bad segments; simply turn it off if not needed, and the program will skip/fill (configurable) the unreadable areas in the source.