@Jack Nichols. Thanks for all the detailed explanations and advice on getting OneDrive to possibly work on a mac. But here's my feedback: If your product requires customers to read long technical blogs on cloud file handling, and fully understand what is going on under the hood in order to safely use your product, you are doing something wrong. In my opinion you are making the classic mistake of imposing solutions you *think* your customers need rather than really listening to them. Since my original post to this forum, I have long since abandoned OneDrive, mostly because I don't have the necessary level of technical expertise nor time and energy to figure out what exactly it's doing with the files, and how to make sure it is playing well with other local backup systems.