Apple today seeded the fourth beta of an upcoming macOS High Sierra 10.13.6 update to developers and public beta testers for testing purposes, one week after seeding the third 10.13.6 beta.
The new macOS High Sierra 10.13.6 beta can be downloaded through the Software Update mechanism in the Mac App Store with the proper profile installed.
We don't yet know what improvements the sixth update to macOS High Sierra will bring, but it likely focuses on bug fixes and performance improvements for issues that were not able to be addressed in macOS High Sierra 10.13.5.
No feature changes were discovered in the first three macOS High Sierra 10.13.6 betas, but we'll update this post if new features or notable bug fixes are discovered in the fourth beta.
Work on macOS High Sierra is wrapping up, with Apple now shifting focus to the next-generation version of macOS, macOS 10.14, which was unveiled at the Worldwide Developers Conference in early June.