That's fine, but you'll have to rename it "efi" before using the installer again. Something must have gone wrong for the EFI folder of the installation not to be created (maybe because of your USB drive). You'll want to boot into the installer and create the boot files again. Because you already tried booting with the wrong efi files (which is especially problematic on the first boot), you might have to reformat and apply the image again. You can also write the EFI files directly to the EFI partition, but you'll have to be extra careful with the Windows bootx64.efi file.
Thanks you for a quick reply.
So start all over essentially?
A few questions-
Does it matter when I hit Shift-f10 to interrupt the ‘normal’ installation process? At the very first screen?
Also you mention ‘Something must have gone wrong for the EFI folder of the installation not to be created’ - the EFI folder was created on the target Windows drive, the EFI was missing on the USB installer. Or does the installation process create the EFI folder on usb stick as well so that I can reboot and continue installation?
Also, when I (hopefully eventually) get to copy USB/EFI/Microsoft to /Volumes/EFI/EFI on the target ssd, do I copy the Microsoft folder itself or only its contents? In other words, should i end up with /Volumes/EFI/EFI/Microsoft ?
Thanks again. Running OC with Windows is a bit of a personal curse it seems, hopefully your new guide will help me break it (I’ve tried more or less everything else under the Sun and am now running a legacy install with bootchamp to switch, which, while it works, does feel a bit antiquated)