I tried CS2 on my Deck after the update. I only tried against bots on Italy but found that given the hardware, it ran surprisingly OK. 40 FPS with default settings. Obviously the controls are not so great. I’ve read somewhere later that resetting Steam Input for this game to defaults is required but didn’t know that at the time.
Btw I played with the Deck on a stand and my left hand on the controller part while my right hand held a Bluetooth mouse.