I suspect this is mainly for Amazon-bought books with highlights stored on Amazon's servers right? Or does this also work with notes made on side-loaded books?
That is indeed correct. We currently only support importing your highlights synced with Amazon's cloud.
It's totally possible to also allow you sync with the notes from books on your device, but the UX is a bit worse -- you've got to physically plugin your device. That being said, it's on our todo list!
It's totally possible to also allow you sync with the notes from books on your device, but the UX is a bit worse -- you've got to physically plugin your device. That being said, it's on our todo list!