I was planning on using the speaker level harness but had some questions...

Manual states that left channel is white for + and white/black for - and right channel is Gray+ and gray/black- but it seems odd the way they lined up these wires on the harness with white and grey on the left a black in the middle and both the white/black and grey/black on the right.... basically just wanted to confirm if the manual is correct here is a very simple diagram of what I am looking at.

Next question I have is why does the speaker level harness have the solid black (ground) wire? Would I need to use this?

Third question: How well does the automatic sense signal work to turn on and off the amp while using the speaker level harness versus the REM remote turn-on input??

FYI: if yall care... I am installing this amp, using a cheapo 8 awg wire set up with 12 arg for speaker wire, to run my 1 X JL 12W1v2 (4ohm) in a tuned bandpass box. This is going in my 2011 Accord.