The main limitation between starter and the paid version is the amount of projects you can create. You shouldn't be limited by cloud back ups, rather the amount of new projects you can make. If you can't create more than one project let me know, as that sounds like some sort of bug. Also, when you have both apps on one iPad it can do weird things with your user account, so we don't recommend having both at the same time. This could confuse how your profile is treated. Which is probably why you're seeing a limitation with cloud backups.