I have a ASUS Z370-A Prime motherboard. I don’t run Windows natively, but do under Virtualbox on Ubuntu Linux.
Asus released an Intel Firmware Update with only a Windows MEUpdaterTool executable.
I Created a WinPE image from my Virtualbox Windows 10 virtual machine, which I dd’d onto a USB, and managed to use the Intel updater tool in the X:\FW folder to complete the upgrade.
So if you find yourself in my position, you can download the WinPE environment here:
Note, the MEUpdateTool in the root folder, is not supported in the PE environment, just CD in to the X:\FW folder and use the FWUpdLcl64.exe tool.
Just, unzip the image and dd it to your USB drive (below assumes that /dev/sdb is your USB drive, check first or you might clobber another disk in your system):
sudo dd if=winpe_amd.img of=/dev/sdb bs=4M