Biggest issue with deletions or additions is they head to the assembly line to be built as is. Not built but with the option to add later. I have had Ford vehicles that were not ordered with towing package. So the main harness going to the back did not have any of those wires to retrofit later. I suspect items like rear climate control deletion will be able to be retrofitted easily since that is a standard non deletion item. IMO the rule of thumb is if you can remove it from the options selector then it "could" be hard to retrofit. If its a standard item that is removed due to chip issue then IMO it can be easily retrofitted.