HI mate,

check you have the correct plug heat range also for the boost you
are running, as plugs will get hot and melt tips, with big damage,and as above check fuel pressure preferably on boost,
co% , and have your injectors flow checked even when
brand new? either wrong plugs, mixture weak, down to pump, injectors
vacuum leak etc, check with who mapped it boost limit,
looking at the picture of the plugs, they look to hot for the boost you
are running(heat range) what are they make and numbers,

DAVE R