I wanted to simplify this so all you need to do is get an API key, select a map region and a zoom level, and get one combined glTF file that you can throw into any engine. Especially if you're just prototyping and want to see how this data looks in your engine before investing in figuring out all the nuances of the API & coordinate system.

(Note that the API prohibits offline use, as in you can't distribute a processed glTF file like this. But you can do this preprocessing in memory whenever you're fetching tiles).