It would be ideal to have our personal books in Logos on the iPad. One day soon, hopefully, that can happen. As a work around just to read a personal book on the iPad, remember that any document that you can convert to a personal book can be converted to an ePub or PDF and read in numerous apps on the iPad. You can then multitask between the document and the Logos app by double clicking the button.
No, that is not nearly as good as having your PB in the Logos app. However, I find it very useful