Even though Valve only just recently put SteamOS 3.5 into preview for Steam Deck, they're not done with improvements elsewhere with a new Beta Client release doing a bit of a Gyro overhaul to the Mouse mode.

Even though Valve only just recently put SteamOS 3.5 into preview for Steam Deck, they’re not done with improvements elsewhere with a new Beta Client release doing a bit of a Gyro overhaul to the Mouse mode.

Patch Notes