It is included here: Useful tools.zip 693.69KB
And can be pre-loaded just like ntfs_x64.efi, before all the other commands.
Could you please try it, I haven't downloaded the August 2021 version to test it myself.
Pre-Load of EfiGuardDxe.efi is working great
Tested for Recent Windows Boot Manager August 2021 of Windows 10x64 and Windows 11x64
On the fly patching allows indeed to Boot Mini 10 and 11 straight from RAMDISK using UEFI Grub4dos (Grub4efi G4E)
So there is no need anymore to Enter OS Selection and on Boot Entry to press F8 for Advanced menu
and Select Disable driver signature enforcement as needed without using EfiGuardDxe.efi
title Mini-10x64b.vhd - EfiGuardDxe.efi UEFI Grub4dos SVBus RAMDISK - 3.8 GB
find --set-root --ignore-floppies --ignore-cd /Mini-10x64b.vhd
map --mem --top /Mini-10x64b.vhd (hd)
EfiGuardDxe.efi is already available on USB drives in EFI\grub\tools when using USB_FORMAT or UEFI_MULTI or VHD_WIMBOOT
So to make use of it you only need to add in your menu.lst entry the line: load /EFI/grub/tools/EfiGuardDxe.efi
EDIT: Grub2 has now as first menuentry to Load EfiGuard - Enter or wait 10 seconds to activate - Skip by selecting other entry
This works for all Windows entries in Grub2 Menu and the chainloaded UEFI Grub4dos (Grub4efi) Menu and the chainloaded Windows Boot Manager Menu.
Thanks to alacran for making me aware of this useful tool