If you want to make your own banners for games in your Steam library the dimensions are 460×215.
Simple way to stream games from a PC to a TV elsewhere on the network. Originally Valve sold a dedicated Steam Link unit, but it's been discontinued in favour of Raspberry Pi, Android, Samsung TVs, and flatpack-based Linux versions.Apparantly you can now even use it over the Internet.
So thr Pi 4's probably the best option unless you find a Steam Link real cheap. The extra RAM and stuff probably doesn't matter, but you can also put Kodi and stuff on there, and will have better support from Valve going forward?
Steam Play is Valve's Wine fork. So, in essence, it's a game-specific version of Wine. A cool thing about this is that it gives you a central place to report game-related issues, and those issues are ones they will be interested in fixing. From Valve's point of view I guess it will give them more accurate numbers on how many people actually use Linux for playing games, without it being so distorted by people running the Windows version of Steam through Wine.
It's still early days, but here are some useful links:
If you want to try to figure out why a particular game isn't working you can add PROTON_LOG=1 %command% to the launch options. It'll dump an error log in your home folder.
You can also enable debugging globally if you want, see: user_settings.sample.py