On some computers, it is not possible to enroll the MOK key for ventoy

[ejrydhfs]

On some computers such as the Lenovo ThinkBook 16 G6 IRL, it is not possible to enroll the MOK secure boot key for ventoy. This is because the BIOS does not support third party Microsoft CAs. The only way to boot ventoy is to disable secure boot.

On the lenovo thinkpad e16 gen 2, it is possible to enroll the MOK secure boot key, but only after either enabling support for third party microsoft CAs in the bios.

[ventoy]

Yes.
Ventoy use shim which depends on Microsoft 3rd-Party UEFI CA.
Not only Lenovo but also some other computers have such BIOS option, such as:
https://ventoy.net/static/img/secure_bios_option.png
https://ventoy.net/static/img/sboot/uefi_ca_thinkpad.png
https://ventoy.net/static/img/sboot/uefi_ca_surface.png
https://ventoy.net/static/img/sboot/uefi_ca_hp.png
https://ventoy.net/static/img/sboot/uefi_ca_dell.png

Only that this option is enabled by default on some computers.

[ventoy]

This BIOS option not only affect Ventoy but also all Linux distros.

That is to say, if third party microsoft CAs is not enabled in the BIOS, the computer can only boot Windows and can not boot all Linux distros (e.g. Ubuntu/Debian/RedHat/...)