Maybe a bit of a red herring, but I just used Kubernetes as a cheap source of mildly interesting JSON to test a diffing tool with. You'll see that the manpage for Graphtage just uses things like '{"foo":["bar"]}' in their examples... and those run fast. But the second you get some real-world piece of data, it takes 5 minutes to run. That's why I tested on some real-world data first.