also check if your system has the reg key listed in the issue

there's always https://www.supergrubdisk.org/super-grub2-disk/

and finally, if you are really concerned and dont want to re-install, you can always take export the registry key of your root certs of a ventoy installed system and compare against a system not loaded with ventoy

edit: can also use systemd to boot iso's (among many other things)