We have just shipped an updated Steam Deck Client to the Stable (default) channel. Note: This client was rereleased on July 10 to fix installscript support for some games General Added playing a sound to some notification toasts where it was previously missing. Fixed wrong auto display scale being chosen for wide displays. Fixed some views being the wrong size on macOS. Fixed issue displaying the system tray context menu.
I don’t think it’s possible to move to a new kernel version in smaller steps.
3.5 includes a ton of new stuff, and I’m assuming it’s not all kernel based. Things like the saturation slider for example.