Because of the very large size of our MyBB database, and the lack of API support in MyBB, I think our best bet might be make this a two-part project:

1. A small CI app that provides an API we define that can read from the main database and return JSON responses in formats we define
2. In the repo we would have our importer queued up to run in batches so we don't get a hanging job.

We would need to whitelist IP addresses for the API, but I think this would allow any of us to develop that feature and get access to the real data to ensure everything works and gets mapped correctly before this gets installed on the CI servers.