Well, installed my D3400 today, resting voltage at 12.9 when I put it in, and it's definitely a huge improvement of what I had before!
Let it run for about 15 minutes after installing and ended with a resting voltage of 13.5
Those terminals definitely set it off, hats off to XS Power and Geoff for making awesome products!
Mechman install should be coming in the next couple of days.