When we do our upgrades (every 3 weeks) of our applications we take the application offline (deactivate in IAM) right before we execute the source code on the database and we put it back online after the IAM sync.
However as time goes on our model grows and the IAM sync action in SF is taking up to 8min right now, the majority of that time goes into generating the sync code.
If we could generate the sync code separately from the actual sync this would decrease the required downtime for upgrades by a big percentage because you could generate the sync code before taking the application offline.
On top of that it is pretty easy to forget to do an IAM sync, it would be nice to have it part of the creation process/screen.