Intel released new firmware update for this audio problem, however its relevant for windows only
Download HDMI 2.0 Firmware Update Tool for Intel® NUC Kit NUC7i3BN, NUC7i5BN, NUC7i7BN, NUC6CAY
Hope it will be part of next LE version....
Intel firmware flashing functions will never be part of LE .. because the fcukwits at Intel only have a Windows (not Linux) flashing tool.