Can we use a Native PDF-task to register unregistered inks in Automation Engine without normalizing the file?
Please use the native "Optimize PDF" task (Added in Automation Engine 18.1.1 onward).
In the Separations tab from the Optimize PDF task, we can fill in a (*) in both the "Old Separation Name" and "New Separation Name". These will act as a joker, and will lookup all the separation/ink names in both the input-file, as well as the CMS database. If there is a 100% match, the separation color data from the file will be updated with the color data from the CMS database. (registering the inks from the input-file). Please be notified that in the event that an ink name exists in multiple ink books, an alphabetical query will be executed.
You can also use this option to "Update spot color equivalents" (as known in the non-native "Optimize PDF separations"-task), when you enable "Spot Color Lookup" in that same Separations-tab from the "Optimize PDF" task.
Here you can see an example of both the ticket settings, as well as two PDF-information windows (Input/unregistered and Output/registered):