I just discovered this library and was browsing the posts. Unless you solved this, I have a suggestion.
Try Freda. I've used it since the Windows Mobile ~5 days and have been happy with it. It also allows linking and download from various cloud storage sites including OneDrive. Though the ability to sync to see the cloud contents on the bookshelf (without downloading everything) has eluded me so far; think about this function as being the way Kindle shows you the books you have on the Amazon library without downloading the full file, just the basic data to name, show the cover and categorize it.
It does allow syncing of reading status across devices using the cloud link which is nice. Also, it has a good Android version to compliment it on tablets.
Good luck and let me know if you use it and figure out that bookshelf sync.