Apple today seeded the fourth beta of an upcoming macOS Mojave 10.14.6 update to developers, two weeks after seeding the third macOS Mojave 10.14.6 beta and nearly two months after the release of macOS Mojave 10.14.5, which brought AirPlay 2 support for third-party TVs.
The new macOS Mojave 10.14.6 beta can be downloaded through the Software Update mechanism in System Preferences after the proper profile has been installed from Apple's Developer Center.
There were no new features or significant changes discovered in the first three betas of macOS Mojave 10.14.6, which indicates it likely focuses on bug fixes and performance improvements for issues that weren't able to be addressed in the macOS Mojave 10.14.5 update.
If new features are found in the fourth beta of macOS Mojave 10.14.6, we'll update this post with details.
macOS Mojave 10.14.6 is likely to be one of the last updates to the macOS Mojave operating system as Apple will soon transition to work on macOS Catalina, announced at WWDC.