Okay, WTF did I just discover

If you go to download-chromium.appspot.com, you can download the latest build of Chromium. Adding /dl/Mac, for example, will take you to the latest stable build for Intel Macs. So far, so good.

But what happens if one does specify an unsupported OS?

https://download-chromium.appspot.com/dl/Commodore

… What even is this? 😂