• Made an adjustment to how CCC copies the contents of the System volume when that volume is getting updated to avoid removing any content from the destination System volume that doesn't belong there. While it is inappropriate to ever have content on the destination System volume (CCC, for example, would not allow you to configure a task in that manner), Finder allows the modification of that volume, so conceivably someone could copy content to that volume without realizing the error. In general, you should avoid storing anything on your macOS backup volume that is unrelated to the source volume. If you want to store other content on your backup disk, create a dedicated volume for that content.
  
  
• CCC detects a couple more error conditions that are commonly encountered during APFS conversion on macOS Catalina and either works around them to make the conversion succeed or presents them with more accurate advice.

More info on Carbon Copy Cloner 5 (including 30 day trial) at bombich.com.