Instance specific archival window

[#1]

We have a business process that involves review of pieces by external entities that may take several months to complete. This results in a proof being archived prior to the review completing and delays in finalizing a piece due to having to un-archive the proof when the review is complete. We'd like to be able to specify the number of consecutive days of inactivity prior to archive (for our instance) instead of it being locked in at 60.