Apple today released the sixth developer betas of iOS 12, macOS 10.14 Mojave, watchOS 5, and tvOS 12, which are the next major iterations of its operating systems. The new builds arrive just a week after beta 5. There aren't really any features being added at this point, ad the firm is preparing for a general release next month.
iOS 12 build 16A5345f presents a few new issues, such as that Settings might crash in Speech settings. There are also still a bunch of known issues with group calling in FaceTime. The only resolved issues on the list have to do with Siri, such as Apple Pay Cash now working properly.
Some of the known issues in macOS 10.14 Mojave build 18A353d have to do with Mac Pro models from mid-2010 and mid-2012, such as having to upgrade to High Sierra before going to Mojave, and being unable to log into FaceTime and iMessage. Other than that, most of the major issues seem to be fixed.
There's more good news. watchOS 5 build 16R5340g doesn't list any known issues that should affect the end user at all. As far as tvOS 12 build 16J5340e goes, there are a bunch of resolved issues, but PIN pairing with an Apple TV might still fail.
As always, it's recommended that you read through the release notes before installing new beta software. We should start to see builds more frequently, as we're pretty much in the home stretch. Apple will announce new iPhones early next month, and there will be GM seeds following the event, and a public release will be a couple of weeks later.