Boot Windows from an external usb drive whithout using the EFI partition on the Mac [duplicate]

I followed this guide to install Windows 10 on an external USB drive. It all works great.

The way to allow the Mac to boot is as follows
(this is done inside the command line when booting from the Windows installer USB):

To make your installation bootable, enter bcdboot W:\Windows /l en-us /s Z: /f UEFI. This will create the boot files in your EFI partition.

From what I understand, the Mac has a partition where UEFI systems can boot and in this particular case boots Windows from that partition and then control is passed to whatever is located on the external drive. I became aware of this here.

I would like to be able to boot this Windows installation from other Macs without running the bcdboot command as that would imply booting the Windows installer and running cumbersome operations.

I also know that a USB stick can boot the system (this is what macOS installer and Windows installed do). So... my question is this:

Can you create a USB stick that boots up the system and passes control to my USB drive with Windows installed on it? Or maybe change the Windows USB drive to allow it to boot?

I don't understand the whole booting process but my guess would be that a bootloader could be installed on a USB stick and that would allow me to boot Windows.

Note: Installing Windows 10 on an external drive has answered several times here a Ask Different. Most notable with the question Is it possible to use Boot Camp with Windows 10 from an external HDD?

Below is a specific answer to your question: Or maybe change the Windows USB drive to allow it to boot? To implement this solution, you will need to reinstall Windows to the external drive. This solution does not include instructions for removing the Windows boot files from your internal drive. You can post a comment, if you wish for me to include instructions.

You will need to make the following changes to Part 4: Preparing your External Drive in your linked article How to Install Windows 10 on an External Drive on a Mac.

Enter the following commands between steps 9 and 10.

    CONVERT GPT
    CREATE PARTITION EFI SIZE=260
    FORMAT FS=FAT32 LABEL=EFI QUICK
    ASSIGN LETTER=Z
    CREATE PARTITION MSR SIZE=16

Skip steps 13, 14 and 15.

References:

UEFI/GPT-based hard drive partitions
Sample scripts