I have been using Goodnotes 6 on my iPad Pro almost a year with my 2015 MacBook Pro running a version behind the requirement. The app works but not the documents created on the updated iPad. I sincerely hope GoodNotes Team able to create an option for syncing that it either can create a general basic compatible option for the documents upon syncing / saving. It's very frustrating that I will have to buy a new MacBook in order to use the sync function and so on. I suggest if possible there are options or patch allows the older version sync with the new version but just with limited ability to the file, or it will be sync but function like AI or others will not work on the older version but preserves settings and function on the newer versions.