Public (without logging in) upload to a shared folder
Make it possible to create a share forlder with Bill, send the link to him at email@example.com and let Bill just click on the link and upload/create files to that folder without signing. Folders could also be password protected so that Bill needs to know that to access the share.
Despite being told "Its done" on this duplicate idea (https://onedrive.uservoice.com/forums/913531-onedrive-sharing-collaboration/suggestions/7347782-upload-to-a-shared-folder-without-loging-in) it is not.
The link https://support.office.com/en-us/article/Share-OneDrive-files-and-folders-9fcc2f7d-de0c-4cec-93b0-a82024800c07 clearly states "Users with the link cannot upload new items" and my tests confirm that.