I would like to see the ability to hide personal books within the personal book builder tool. Why? Because the list gets too unwieldy. There are a number of books which, in my mind, are "complete." I could simply delete the PB from the PBB, but I MAY need to edit something in the future, so hiding it would be preferable.
If I could hide PB's in this way, I would keep in the list 4-5 PB's that I am currently creating, along with those which by nature get continually updated.