1. That's OK. The USB drive was created by Windows's Version of Ventoy, you can also update it with Linux version of Ventoy. The reverse is the same.
2. GPT partition style will be kept after update, no need to set option. But for Secure Boot Support you must use -s option in Linux version to update.
That's sh Ventoy2Disk.sh -u -s /dev/sdb
Supergrub2 sounds good.
But the secure boot solution in Ventoy need to be redesigned. It wil follow the original intention of secure boot.
Only boot those .efi loader with valid signatures.
2. GPT partition style will be kept after update, no need to set option. But for Secure Boot Support you must use -s option in Linux version to update.
That's sh Ventoy2Disk.sh -u -s /dev/sdb
Supergrub2 sounds good.
But the secure boot solution in Ventoy need to be redesigned. It wil follow the original intention of secure boot.
Only boot those .efi loader with valid signatures.