Azure Marketplace charges
I'm not sure there is anything you can do about the poor information you get from the Microsoft billing API but it would be great to see Azure Marketplace charges on any reports
Azure Marketplace usage is now available for Enterprise Agreement (EA), pay-as-you-go (PAYG), and Microsoft Customer Agreement (MCA) accounts in the Azure portal and using API version 2019-05-01-preview. Let us know what you’d like to see next!
i do not think Cost management API's require a lot of changes, but yes, a bit of new hooks will be appreciated.