Beautiful quiilt!
What does your wool batting recommend for the quilting?? Generally, if it says 5" (or whatever measurement), that means 5" in any direction. Personally, I would be hesitant to do channel quilting, as obviously it would not give any cross quilting to hold your batting.
IMHO, and yes, only IMHO .... for simplicity, I would highlight the design, doing straight line quilting following the large diamond blocks of the design. That would really help show of your amazing 3D design.