I've just updated my GP5 to the BEANSTALK KK ROM. As with the other KK ROMS I've tried, the MAC address is set (and can be changed) in the nvram_net.txt file in the vendor folder, rather than by the EFS folder. The question I have is about the country code (ccode)in the same nvram_net.txt file. In the three KK ROMs I've tried, it is set to KR. Does this overide other settings on the GP5, and would changing it to US cause any problems?