So, Apple could fix this problem by changing to Boot Camp Assistant to format the USB flash drive as ExFAT instead of FAT32. Mac computers running High Sierra or Mojave may be able to boot from USB flash drives that are ExFAT formatted. Here are three potential ways to create the USB installer. I have found that after upgrading to High Sierra, my 2013 iMac could boot the Windows 10 installer from a ExFAT formatted USB flash drive.
