How to change 'Ship To Location' to a different Org location after PO is approved?

We are currently on 12.1.3 and in a process to upgrade to 12.2.12 next month. During our Unit Testing, we found that we can no longer change the 'Ship-To Location' from one Org location to a different Org location after a Purchase Order gets approved. We use Buyer Workbench currently and this has worked as expected since we went live back in 2010. On the Java core form, this never use to work and ‘Ship-To Location’ use to lock-down after PO gets approved.

The reason we change our 'Ship-To Location' to a different Org is when there is a long lead time for an item, and we do not know the final location until the location is setup. I would like to understand how other companies are managing such scenarios, where there is a long lead time, and the final location is different than what the initial Purchase Order was approved for?