I have a few scratched CDs that I cannot rip using CUERipper because I'll inevitably get an exception partway through the rip, such as "Exception: Error reading CD: medium error: L-EC UNCORRECTABLE ERROR", a message about CIRC failing, a generic error saying the read command failed, or something similar depending on which drive I use to read.
This almost happens during one of the retries of a given section, not the initial read. My last three attempts to rip a given CD it aborted at 39% on retry 6, retry 21, and retry 2. This indicates to me that even just retrying the failed operation would likely succeed, as it has already succeeded on several previous passes. (By succeed I mean the operation completes and returns data, not that the data is necessarily 100% correct.)
Even if a given sector can't be read at all, CUERipper should continue to the next sector and finish the disc. It seams silly that one sector that can't be read should prevent ripping the entire disc.
The start of the second paragraph should be "This almost always happens…"