Honestly, I wrote the tool in about an hour for a good friend, just to make a quick solution for a specific problem they were facing. Since it turned out to be quite useful, I thought I’d share it with the community as well. I'll drop the source code here later for anyone who's interested. In this way, others might benefit from it too, and who knows, it could be helpful to some people facing similar challenges. Also, we could probably expand on it in the future and add some more upgrades that are still on the way
This update now enables also the creation of a bootable USB stick formatted as FAT32. For a Windows installation medium to boot from USB sticks in UEFI mode, it should be formatted in FAT32. However, if the install.wim file exceeds 4 GB, it cannot be written to a FAT32-formatted medium like a USB stick. While the UEFI specification doesn't explicitly prevent booting from NTFS media, it mandates support for FAT32 booting. For a UEFI/GPT installation of Windows, an EFI boot partition must be formatted as FAT32 on the target drive, as I read from Microsoft. Since Microsoft often increases the size of install.wim, it eventually surpasses the 4 GB limit, making it impossible to copy to a FAT32 USB stick. To address this, I split install.wim into two install.swm files, which are reassembled during setup.
I've also realized that UEFI systems expect the EFI System Partition (ESP), which is used for booting, to be in FAT32 format. That’s because UEFI firmware uses FAT32 to access boot files like bootx64.efi. If your USB stick is formatted in NTFS, your UEFI system might not be able to boot from it, as many UEFI systems don’t directly support NTFS without specific drivers or tweaks. That’s just a side note and doesn't need to concern you too much, but to sum it up, FAT32 booting is more reliable for me. The official Microsoft Media Creation Tool does it the same way.
Additionally, I have not yet integrated a Flyby (which I now call it, but you know I'm referring to a bypass) that injects a skip for hardware requirements directly into the ISO during Media Creation. I still need to explore this further, as boot media have never been a focus for me. Throughout this process, I use only built-in Windows tools like DiskPart, Robocopy, and DISM without relying on external bootloaders like Rufus.
More info
