another buggy feature. I am patiently trying to find a use for their cloud feature...
a book can be in 3 states, local, synchronised, or " archived" = cloud only
so using their user guide as a test book, since it is easily re-downloaded if lost - I read the chapter about cloud, and then I archived it. So far so good, but then i could see NO way to "un-archive it" . and any instructions were in the inaccessible archived book

now that could just be me being dumb so if anyone can easily archive and un-archive from the same device - do tell please
Related issues that I did not fully check
1.when you sync a book it is moved to the bookari sync folder. when you un-sync it does it get put back to where it originally came from ? I suspect not. I suspect it becomes an unsycned book within the sync folder.
2. there are 2 ways to delete a synced book. [ now this test was in my v3 install so it way be slightly different in v4.] one is the obvious tick it and tap delete in the footer. but the user manual says tick it then long tap the sync button until you see an options menu. that has stuff like delete book only or book and notes, and the option to delete here or delete everywhere.
so it is uncear which permuation the simple " delete option defaults to