Ignoring fatal errors. dvdisaster will normally abort the scan when the drive reports a fatal internal error like mechanical problems. The intention is to avoid damaging the drive. However some drives will erroneously report such problems when they get confused by damaged media. If you have such a drive you can use this option to force the scan to continue.

Eject medium after sucessful read. dvdisaster tries to eject the medium after a successful scan if this option is activated. However ejecting the medium might be prohibited by the operating system so this is not guaranteed to work. For example if upon media insertion a window is opened for performing the contents it may not be possible to automatically eject the medium.

Skipping sectors after a read error. Attempts for reading defective sectors cost a lot of time. Since it is likely to encounter another defective sector after hitting a read error, skipping a few sectors after a read error saves time and reduces wear on the drive. If you only want a quick overview of a damaged medium setting this value to 1024 might help. But keep in mind that all skipped sectors are treated as being defective so the number of reported errors becomes higher and less accurate.