I've changed my mind on the issue of using a database. I now thing that Revit should use a database and provide built-in tools for manipulation of keynotes, sharing them and synchronizing them in a multi-user environment.
I changed my mind after I investigated how Vectorworks deals with keynotes. Pretty much everyone else does it better than Revit. COME ON Autodesk, you've had years to address this. You're now past the point of just providing some basic functionality from 10 years ago. You now have to look towards the future and give us something even better and longer lasting. A flexible tool that is powerful to implement a variety of user-customised workflows when it comes to keynoting. If you decide to go ahead and give us some love, then please don't limit us to two fields: key and note. We should be able to add more fields, arrange them how we see fit, have better support for text alignment, note alignment, leader placement. The whole works!