ProtonUp-Qt is great. A very simple application that allows you to download extra compatibility layers for Linux desktops and the Steam Deck and now it's even better. This tool helps you install GE-Proton (formerly Proton-GE) and Luxtorpeda for Steam, plus it also helps with Wine-GE for the game managers Lutris and Heroic Games Launcher.
The latest release, ProtonUp-Qt v2.6.2, is out now adding in the display of official Proton in the game list, a new column to show expected Steam Deck compatibility in the game list and performance improvements.
Here's an example of how it looks:
Need a guide on how to use it? See my previous article.