They are, I tested some of my 100 gb and 50 gb discs and the checksums matched with the original files on my hard drives, so the layer break didn't effect me at all with my verbatim Blu ray m discs and lg wh14ns40 and wh16ns40. I don't know about any optical media testing software, testing the checksums seemed like the easiest way to verify file integrity to me. And I didn't just verify one file on the disc, I made sure to verify all files on every disc I tested and all the checksums matched on the discs I tested. And i only tested checksums on the discs I burned that had a few very large files, beacuase getting the checksum of hundreds of small files would have been extremely time consuming. And all the discs I burned/tested were udf and for archive storage.
Oh and I lost my account info, and couldn't log into because I was locked out from too mang attempts so I just made a new one.