Just going back over all my research before I install my deck next weekend (hopefully) looking at this video from Wrathernaut's sticky. My question is, What is the reason for having to do this?

 

Specifically for 03-04's, the JDM climate never had dual, so you had to do it.

For 05+, sometimes you get a good deal on non-dual climate control, so you have to transfer the button to save yourself $20.

Most places have the dual climate control boards in stock at the same price as non-dual climate control, so it's not necessary very often.

 

Got it, so it's a workaround. The board I got from Grubbs is a dual-zone so I won't have to bother then. Yeah?

 

Correct.