r/BookFusion

I want to sync my calibre Library to BookFusion using the BookFusion Plugin. The library holds 5,000 ebooks. I seem to have reached a block with 2,400 having been successfully synced. The plug keeps stopping at this number of synced books despite deleting the 2,401th book a number of times (a different book each time)

IS THEIR A BOOKFUSION LIMIT THAT IS BLOCKING?

Is the Bookfusion Koreader plugin still in closed beta? The support pages on Bookfusion do give instructions on how to install it and make it work, but they don't say where to download the plugin from. I really want to try it so any information would be welcome.