Apple has seeded the second developer betas of iOS 16.4, iPadOS 16.4, tvOS 16.4, and watchOS 9.4 for testing.
Second developer betas are here
Developers can download the latest builds by taking part in the beta testing program via the Apple Developer Center. Public beta versions of the releases generally arrive a short while after their developer counterparts, available through the Apple Beta Software Program.
The first betas of iOS 16.4, iPadOS 16.4, watchOS 9.4, tvOS 16.4, and HomePod software version 16.4 arrived on February 16. New features include more Shortcuts actions, additional always-on display controls, and Mastodon rich previews in iMessage.
Also, starting with iOS 16.4 and the other releases, users will no longer install profiles to control beta access. Instead, devices must be registered to the Apple ID for beta updates to show up in Settings.
The second iOS 16.4 and iPadOS 16.4 betas have build number 20E5223e, replacing build 20E5212f. The second beta of watchOS 9.4 has build number 20T5233d, replacing build 20T5222g. The new tvOS 16.4 and HomePod software version 16.4 build number is 20L5474e, up from 20L5463g.
AppleInsider and Apple strongly advise users don't install beta operating systems, or beta software in general, on to "mission-critical" or primary devices, as there is the chance of issues that could result in the loss of data. Testers should instead use secondary or non-essential hardware and ensure they have sufficient backups of their critical data at all times.