As soon as Apple posts a 'Golden Master' build of High Sierra, we will proceed with our last push to update documentation, screenshots, videos, etc.
We've posted an update to CCC 4 that fixes a couple cosmetic High-Sierra-specific issues, and we're preparing to release an update to CCC 5 with the same fixes, plus more improvements that are specific to High Sierra. We've been busy testing High Sierra over the summer, and I'm happy to say that we're ready for it. On Tuesday Apple announced the release date for macOS High Sierra – we can expect to see it on the App Store on September 25.