With references gone, objects are the only user of C4Value::NextRef. And the only purpose is to keep a list of all variables that contain a given object so that they can all be set to nil when the object is removed. I suspect that removing that list could speed up C4Script a bit. The engine already has machinery in place to deal with references to removed objects: They are kept until the end of the frame and then removed. We could easily extend that to keep objects that have references from script. That would have observable implications for scripts, though, so I'd want to study scripts that rely on variables containing an object changing to nil on RemoveObject/Explode/Sale/etc. of an object. Does anyone know examples? Do you routinely check a variable for nil to find out whether an object still exists, or do you use the Destruction callback?