Make it possible to upload large folders (first time upload) without requiring addl local disk space
Today's laptops often have 256 GB SSD space only. There is insufficient room for the local OneDrive folder - hence the need for Cloud space. But your app is hopeless because it requires space for the initial upload. Using the Online Upload function also is not workable because Uploads often don't resume once interrupted. Interruptions can occur because of error messages from the Upload process or Windows 10 issues.
I recommend that you look at the services offered by 2BrightSparks (SyncBackPro) and pCloud - they have solved these problem beautifully.