In the configuration dialog it would be nice to be able to delete a BoKeepBook after a really strong "are you paying attention" warning about the number of transactions in a book.

But removing the reference from the BoKeepBookSet isn't the same thing as deletion. A BoKeep shell may have references to it in both its permenant storage (so the shell knows which book to display on open after close) and/or in memory while the shell launches the config dialog.

Some serious team discussion should be had about how to do this right before proceding.