OneDrive for Business Sync Client

Analyzing network logs would be the way to go here. Filter on the onedrive.exe process and just monitor upload/download traffic. And while you can upload network logs to Cloud App Security, it's real use case it to detect anomalies rather than monitor and log all network activity.

Regarding the bandwidth calculator, I would advise not using that tool any longer, since the estimations are not completely accurate - hence the reason the tool is no longer available for download.