I just received the new design PCB. After assembly and some fly wires job, everything works fine.

And I got a comment from Louis S. He said that if I choose the RJ45 port as the IO port that someone may plug it into the network equipment which may cause the device damage especially when the RJ45 port was plugged into which supports PoE.

So I decided to follow the original  PiKVM Hat design and placed the optocoupler between the GPIO and the RJ45 port. This change means that the RJ45 port no longer transceivers the USB signal, we will still need 3 cable features all function.

The change for the fly wires job and place optocoupler for signal isolation will be present in the next version PCB.