My manager has restricted my use of Ventoy.

[nguyen ha thai trong]

According to your description, I guess it's a Windows Secure Boot problem, so when using Rufus, you can boot directly from windows.iso without getting Secure Boot errors? Or you used Rufus to write windows.iso to USB and when booting in UEFI there was no Secure Boot error. You can also bypass Secure Boot with ventoy like using Rufus, the job is very simple, just format the ventoy partition as FAT32, then extract the contents of windows.iso to the ventoy partition (first partition of the USB).

Whether you use ventoy or grubfm, or aioboot, the nature of these 3rd party bootloaders (not from Microsoft) makes it inevitable to encounter Secure Boot errors.