By default, controller layouts won't immediately work, but there are multiple fan software that works fine in giving full access/control. Steam Deck Tools will very easily just make it work in that it will allow you to use it as a controller, but I use Handheld Companion because I can map the ... button to keyboard, STEAM to showing the home screen, and the back controls I've mapped to changing mouse modes or even screenshots/recording. You really have tons of flexibility and these software get updates often for more features.
Steam Deck Tools also has options for other Steam OS features like FPS/performance tracking, fan control, etc. so I'd recommend checking them out if you do end up going with them. There's also other software for similar purposes like Glossi and SWICD, but those have a few issues/are a bit outdated versus Handheld Companion and Steam Deck Tools.
TLDR: works pretty well!