Grub rescue disk is nice for when you fuck up your boot loader. Can detect many installed OSes and allow you to get back into them and fix things with less fussing around https://www.supergrubdisk.org/super-grub2-disk/

It’s been a while since I set mine up but iirc yes. Either that or ventoy creates a partition itself during install specifically that it searches to populate the list when you boot it. The nice thing beyond that is it even lets you explore other disks on the system. So if you have other isos on an unencrypted drive installed in the computer you can also browse to that and boot from it.