I'm in a 2018 4runner and used the TO2 harness for an alpine headunit I just installed but i think the typical two connectors that don't end up being used from the harness are the Orange for illumination and the yellow/black for the foot brake, unless your radio harness requires those two. What loose end connections do you have from the TO1 harness and the Kenwood Harness?
I saw the antenna adapter when I went through the pages when my dash was apart. The install guide didn't make it that clear that splicing was required.
Did you end up with a connector in the TO1 that didn't mate to anything?