In the future, we may want to send an upgrading event after each record (or maybe after every 10 records?) so that client apps can display the progress of the upgrade.  If we had an easy way to do this in the media apps, I'd ask you to add it here because the upgrade times are long enough that we ought to have a spinner or progress bar displayed while upgrading.  But I think we just need to land something and get this bug fixed.