Thank you @JerryChang for your reply.
According to this Wiki page Seeed is flashing their custom boards with SDK Manager.
you’ll need a customize the pinmux spreadsheet if a board schematic differs from developer kit carrier board.
I don’t think this procedure should be made by the clients.
We bought a product from a company, in this case Seeed, and we expect this product (J101-v2) to work out of the box, at least similar to the DevKit as they are stating on their product page.
In our case we can’t configure the 40pin header with sudo /opt/nvidia/jetson-io/jetson-io.py and I explaind here what is happening.
After a few emails with Seeed’s customer support they sent me to NVIDIA forums and try my luck here.
My basic questions still remain unanswered:
a) Is the 40pin header(SPI pins/interface) supposed to work on their J101-v2 custom board?
b) If the answer for the first question is YES why Seeed’s customer support is not helping me with that?