Retaining access to EV and EV.Cloud without affecting EV shortcuts in Outlook

The scenario: We have a client with both an on-premises EV solution and a recently implemented EV.Cloud solution for archiving email in an Exchange 2010 environment.  The EV.Cloud solution was enabled 25/03/2014 when Exchange journaling was pointed to the EV.Cloud service.  Since then we have pushed the Personal.Archive folder to each active user.

Both archives remain enabled.  The on-premises EV solution is set to journal always and archive mail after 91 days.  The Exchange journal is uploaded to EV.Cloud in parallel.  We want to reduce storage used by the on-premises archiving solution, but allows the user continued access to the stubbed emails pre-25/03.  All other email is deleted after 90 days.  The goal is to stop journaling and archiving to the on-premises EV solution altogether and archive to EV.Cloud only, but leave users with access to the old, on-premises EV archives.  We did not disable the on-premises archiving because concerns were raised that once an Exchange policy is implemented to delete emails older than 90-days, the emails shortcuts would also be deleted.  The user community accesses EV archived email via the shortcuts rather than the web page; this is what they are accustomed to.  However; they also have the Personal Archive folder so using the same method to access the on-premises archives might be acceptable. 

The following options we are aware of to achieve the goal are:

1. First option: implement an Exchange-based policy incorporating a Powershell script that excludes email either :
   1. before a specified date
   2. or by the message class (IPM.Note versus IPM.Note.EnterpriseVault.Shortcut)
2. Second option: use mailbox quotas and force the user to manage mail volumes
3. Third option: Use a 3rd party applet/widget to implement the policy as described in option one (similar to OutlookSpy)
4. Fourth option:
   1. Use EV Outlook add-in to access the EV search page via the EV Tools menu and expire the short-cuts
   2. Use the on-premises EV Web page to push an archive folder into each user’s Inbox via the EVPM tool , which is similar to how the EV.Cloud folder is pushed.  Then we run the short-cut expiry set at 0 days to remove all shortcuts

We are looking for information on how to implement each option (other than option 2) to determine which might be the easiest to test and implement.  The client may accept a change in how they access EV archives but we will need to manage the transition carefully.

To note, we are recommending the client ingests the on-premises archives to the EV.Cloud service, but need an interim solution until this is approved to begin.