CMatt,
I just got the Center Console for my 2015 Tahoe PPV, I will be working on taking out the center console and taking pics of the connector end so you can build the harness.
As for the IO3 to IO6 upgrade I am looking at parts now, I know I need the HMI2.5, Radio module with apple play and android and navigation module if I want nav and the 8 in screen and sirrus radio antenna. I know infotainment sells a complete package for a little over 2k which is 90% plug and plag but there is still some wiring that has to be done.
Last question, is it possible to go from a key ignition to a push to start on the PPV?