I am from Norway, and love the idea of a site that summarises all available settings and resolution/framerate support.
As I do not buy a whole lot of PC games in my daily life, I did some edits to the TrackMania United Forever and Treasure Adventure World pages anonymously, as I felt I wouldn't have been able to contribute enough to PCGW for it to be worth it to get an account for it. Eventually I finally decided to make an account 9 months later.
After some time I ended up creating a list for macOS 64-bit games, initially as an experiment to see how dramatically Apple had messed up the gaming sphere (They had messed up roughly 80% of it in 2019). Soon afterwards I made lists for PowerPC and ARM games for all OSs, and began looking online for games to fill up the lists with, and the rest is history.
How I test for certain infoboxes
OS X 64-bit: Any one of the following three: It's visible on Mac App Store on my Big Sur 2014 Mac Mini; It's a part of Apple Arcade; It's known to support Metal; Its system requirements mention 10.15 as a requirement or recommendation.
Linux PowerPC/ARM: I look up the official repos of (in order) Debian, openSUSE, and FreeBSD FreshPorts. For some commercial games I google around in the hopes of finding forum threads about trying to run those games.
Windows ARM: Usually I do some google-searching specifically for Microsoft Store, to find games there whose system requirements explicitly mention ARM support.
Generic/Other controllers: I use a Trust GXT 540, which features a flip between XInput and DirectInput and was reasonably cheap.
Surround sound: I use two pairs of USB speakers to emulate 5.1 (Windows allows specifying that one lacks center-speaker and subwoofer when turning on 5.1).
4K Ultra HD: I have an LG 43UH603V-ZE TV, paired with a Yamaha RX-V685, ensuring 4:4:4 (i.e. 4K with HDR at 60Hz).