OK, so I signed the CLA, and started digging through the code, but I have no experience with Ruby and have no idea where to look. I found https://github.com/discourse/discourse/blob/master/app/assets/javascripts/admin/templates/reports.hbs, as well as https://github.com/discourse/discourse/blob/master/app/assets/javascripts/admin/models/report.js.es6, but they only seem to control what appears when viewing the report on the web. https://github.com/discourse/discourse/blob/master/app/controllers/export_csv_controller.rb and https://github.com/discourse/discourse/blob/master/app/assets/javascripts/discourse/lib/export-csv.js.es6, seem to control the csv creation, but not what is stored in the csv.
Can you point me in the right direction?