iOS 16.4 brings new toggles in Software Update that let you install developer or public betas of iOS without downloading configuration profiles.
iOS 16.4 lets you enroll in betas via Software Update
iPadOS 16.4
iOS 16.4 adds 5G Standalone support for up to 3 Gbps iPhone speeds
Your iPhone could soon support T-Mobile's 5G Standalone network with speeds up to 3Gbps thanks to iOS 16.4, which also brings 5G support to more regions.
iOS 16.4 enables rich embeds for Mastodon links sent via iMessage
Mastodon links are displayed inline in Messages threads on your iPhone as native embeds that include rich details like the post text and author name.