Of course, there was a typo in the doc. The path to create a job is "/bulk/v1/leads/export/create.json" not "/bulk/v1/leads/export.json". I've corrected the docs.
This is possible today using a little elbow grease and the Request Campaign API. You can follow the pattern described here: https://developers.marketo.com/blog/sending-transactiona...
The secondary attributes will be a JSON structure inside of the “attributes” column if you choose to export as a spreadsheet. If you choose JSON, it will be an object in the “attr...