Each time when I spoke with Launchpad team I got a feeling that blueprint part of it is unwanted child which no one want to talk about.
Adding workitems as bug links allows to work around lack of history but they people which are subscribed to BP does not get updates from bugs.
Anyone with permissions can edit whiteboard and there is no way to check changes in other way then go through emails which many people delete just after reading.
I do not like this system but can accept it work.