Another update! Using custom classes is now possible by placing the JS file in a special folder. The next step is some clean up and adding instructions for this new feature. I never use custom classes so I can't easily test if it works with all custom classes out there. I'm sure I'll get feedback about that soon enough with the next release.
For now, here's the JSON of your character: https://pastebin.com/BfiRPGxd
You can save that to disk and import it via Foundry.