Steam Deck Client Update Reduces Black Screen Flashing, Adds New Pixel Scaling Filter

The Steam workshop also gets several QoL improvements.
SteamOS 3.5.5: The Biggest Steam Deck Update of the Year!

Display color adjustments, HDR, VRR, undervolting controls, updated Arch base…
Steam Deck Client Update Adds Visual Tweaks to UI, HDR Badges for Supported Games

Plus easier toggling of Steam Input being on or off.
Steam Deck Client Update Allows You to See Shader Cache Size, Adds Low Latency Option for Streaming

Plus support for the PowerA Switch Nano gamepad.
Proton 8.0-4 Adds Compatibility to Star Wars: KOTOR II, Fixes Overwatch 2 and EA Desktop App

Plus NVAPI support for nearly two dozen titles and bug fixes for a dozen more!
Steam Deck Client Update Adds QoL Improvements to Notifications, Improved Responsiveness of Systray

And 38 bug fixes!
Steam Deck Client Beta Adds Spoiler Alert for Hidden Achievements, Fixes Screenshots for Non-Steam Games

Four beta updates and one stable.
Steam Deck Client Update Fixes UI Overlay Soft-Lock, Improves Support for Third-Party Switch Gamepads

Desktop Mode gets plenty of fixes.
Steam Updates User Interface, Adds Note Taking System, Enables Hardware Acceleration on Linux and Mac

Most of these changes have also been incorporated into the Steam Deck.
SteamOS 3.4.8 Now Stable, Fixes Splitgate and Improves Performance with Star Wars Jedi: Survivor

SteamOS, or Steam Deck OS?