Yes, prior to the 1.10.2 release, currently an individual curve object must be created for each HVAC component that references it. This is because curves inherit from ModelObjects, and are 'children' of the HVAC component (see the 'Relationships' section here), rather than inheriting from ResourceObjects, which can be defined once and referenced by other objects in the model.

This has been There is some changedmovement to redefine curves as ResourceObjects as ResourceObjects, so that you would only have to create one and assign it to multiple systems. @Kyle Benne can give us an update about the status of version 1.10.2. Thanks, @Kyle Benne! that work.