Update title block event - will it be triggered by an import to a page 2 attribute?

Our use case is:

We control 3rd party access to some our parts by a page 2 attribute containing the user id of of the authorised person and criteria on the privileges on that type of user, so they only work with the subset of parts they are named on. We manage this using import to add the user to the attribute for a block of parts en-mass, typically an assembly and its subcomponents.

We need to do similar for designs as we have sub-contractors who will work with out CAD data directly, but there is no import for file folders to update a similar attribute on the designs subclass. So I was thinking of a PX to copy the user from the part attribute to the design attribute where a relationship exists. Of course I need to trigger off the import event that updates the pg2 on the part.