Any program of sufficient complexity ends up having to work around behaviors that are undesirable. That might be a usability issue caused by default framework behavior, due to the interaction model selected by the designer. Or it might be an OS issue that only shows up in some situations (the recent iOS calculator bug is a good example of that).
Most, though, don't have to deal with the huge variation of hardware, software, OS, etc that a program like SuperDuper! has to handle.
The vast majority of the beta cycle has been focused on getting coverage of as many systems as possible. With a broad range of different setups and configurations, we can then find issues in the way macOS 10.13 is dealing with those configurations, and try come up with workarounds so, when when we release the GA version of SuperDuper! 3.0, the broader user community will have a smooth experience.
A lot of these changes have been focused on attached volumes, incorrect state information being returned by macOS calls or tools in some configurations and states, and coming up with ways to prod and probe until macOS returns the correct data.
It can be challenging to do, since you don't want to break "working" setups, and any workarounds should only come into effect in situations where they're needed. That way, when the OS problems are fixed, everything continues to operate.
All of that is a longwinded way of saying, we're happy to release Beta 6 of SuperDuper! 3.0, which has even more workarounds for macOS issues, covering a broad variety of situations we've seen in the past week or so. (It's workarounds all the way down!)
The new beta should work better on every system, and it fixes a problem with the beta autoupdate mechanism as well...so the next release's autoupdate should work better.
Download away, and thanks!