It appears those who dock their Steam Decks and use external monitors are going to be very happy soon! Valve seems to be testing options to enable and disable both Variable Refresh Rate and Tearing.
Variable Refresh Rate, which is the more significant of the two, allows a compatible monitor or tv to allow its refresh rate to change and match the output of the device connected to it, which will create a more fluid and better gaming experience. AMD and Nvidia have both made their own versions of this, but the one that the Steam Deck will use is AMD’s version, Freesync.
For some, it appears that a fluctuation in the code for the preview beta has accidentally enabled these two options to appear. This is not the case for everyone, as I have gone onto the beta preview and it wasn’t there, but it does indicate it is under development.
In the Steam Deck Homebrew discord server, user Lbibass posted a photo showing they had options to enable and disable both VRR and Tearing. These options showed up without being connected to any external display.
After discussing with them a bit on discord, we came to the conclusion that it was possibly a UI glitch and these options have 0 effect on a Deck that is not plugged into an external monitor. This was effectively confirmed by Pierre-Loup Griffais on Twitter when he posted about the implementation of VRR that has been popping up:
Regardless, this is still really welcome news! Having VRR support for external monitors will allow use of Freesync and a way to toggle it on and off! No release window is planned for this update, but we will be watching like a Hawk to see when it will come out!