this is a very good idea.I was under the impression 70.00.100 NA was only necessary if upgrading from a pre 70 version. I was able to find 100 NA and 352B NA on the HiDrive (this is where I got them):
I ran permanent serial wires from the head unit to the glove compartment when I first had everything disassembled to install the official AA/Carplay hardware. Way easier to just remove the glove compartment for serial access in the event I ever need it again in the future.
I will do that same and reserve the pins out for easy access.