When you have an existing blueprint with a compact circuit and then update the blueprint by going into it and selecting a new area for the blueprint, the new blueprint's compact circuit doesn't save any of its internals. I was using packed mode, not sure if that makes a difference.

Additionally, a blueprinted compact circuit loses its title. I'm not sure if this is intentional, because you could have different models of circuit with different names potentially? But if that's the case I really need to be able to see the model of the circuit I'm in labeled somewhere, so I know if I hit apply to a model which circuits are going to get modified.

Blueprint update is not working if the blueprint is in a blueprint book. To update a blueprint, put it in your inventory, update it and put it back in the blueprint book. I have never found how to make it work in a blueprint book.