Apple on Monday issued third betas of macOS 10.12.5, watchOS 3.2.2, tvOS 10.2.1 to developers, including no more than minor bug fixes and security improvements.
No significant release notes accompany the new beta software releases. Given that they aren't full "point" updates, they contain only bug fixes and minor revisions to problems introduced with more major revisions on March 27.
The finished version of macOS 10.12.4 was also released on March 27 and brought minor enhancements, like Night Shift for the Mac, new PDFKit APIs, and more options for iCloud Analytics. It also expanded internet recovery options, but introduced a bug affecting USB audio controller chips for some users that is still not rectified.
As with all the previous betas, the tvOS beta must be installed through a USB-C cable connecting the device to iTunes. The watchOS beta is installed with the watch on the charger, and in range of the paired iPhone. Registered developers can download the beta over-the-air from a device in the beta program already, or from the Developer's portal.
The last round of developer betas were made available on April 10.