I keep my mlo file in the OneDrive folder, and I have not had any trouble keeping it sync'd both ways. When ever MLO syncs with the cloud, then it modifies the file and of course when OneDrive detects a change, it syncs that with the onedrive cloud.
The only trouble I know is multiple users, where OneDrive has a conflict if two computers changed the same file in each OneDrive folder because it requires the change on only one of those and synchronize itself to the other.