Author here, this is my fault for not proof reading this part properly! The part about non-Japan SKUs is generally true for Android phone manufacturers, but Apple eats the cost and gives all phones Osaifi-Keitai. You do not need to root an iPhone to get this functionality, even on a non-Japan unit.
I will write a correction for this section to clear up the confusion.
I will write a correction for this section to clear up the confusion.