I have Windows 10 Pro installed on a external flash drive, I tried to install Windows via bootcamp but it is required to have more free space. I succeeded to install Windows 10 with VirtualBox on a SanDisk 32 gb flash drive and boot into Windows 10. The drive capacity is too small so I bought a Kingston Kyson 64 gb USB 3.2 flash drive, but it will not work with Bootcamp.
If I fresh install Windows with VirtualBox, the installation process will stop around 40% and reboot to EFI interactive shell.
If I clone SanDisk > Kingston from another Bootcamp machine, the clone drive will boot to Windows loading screen followed by BSOD.
If I clone SanDisk > Kingston from the booted Windows 10 drive, the clone drive will boot to Windows loading screen followed by Startup blue screen.
If I clone sector-by-sector, the clone drive will boot with BSOD 0xc0000225, 0xc000000e, Missing / Damaged Winload.efi.