SUMMARY Currently it is possible to read annotations done on Kobo Elipsa in Okular. But the other way around is not true. Most annotations done in Okular are invisible to Kobo Elipsa. The only visible annotation is the free-line. Why not make other kinds of annotations (highlights, text additions) compatible as well? It would be very useful if they were. Or is it something that Kobo needs to implement?
Seems to me this is a Kobo bug, the annotations we create render in Adobe Reader, so that means we're creating a good PDF file, if Kobo doesn't understand them seems like a Kobo bug. Please reopen this bug if you find a case in which Adobe Reader does not understand the things we create.