For possible high-power/current use of ROBOTIS actuators via DXL SHIELD (MKR type) or OpenRB-150 or U2D2 PHB, my own approach had been to keep the Power Circuit (12V at 10A - i.e., via VDD and GND pins) and the Control Circuit (5V and low current - via DATA+ and DATA- + GND) SEPARATE.
More details of the approach and circuit design can be found at this post:
It is a simple solution for just disconnecting VDD line from Control Circuit’s connection to Power Circuit via those X3P TTL or RS-485 Robotis Cable Assemblies.
You are located in Korea, so may be ROBOTIS HQ in Seoul can sell you a few of these X3P TTL or RS-485 PCB hubs?