It turns out that neither renaming `/EFI/ubuntu` created by Linux Mint to something else, nor running `grub-install` with `--bootloader-id` option would allow to have both Linux Mint and Ubuntu GRUB EFI executables on the ESP, here is a related bug:
"grub-install with --bootloader-id option creates unusable boot configuration with secure boot" https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1450783
It turns out that neither renaming `/EFI/ubuntu` created by Linux Mint to something else, nor running `grub-install` with `--bootloader-id` option would allow to have both Linux Mint and Ubuntu GRUB EFI executables on the ESP, here is a related bug:
"grub-install with --bootloader-id option creates unusable boot configuration with secure boot" /bugs.launchpad .net/ubuntu/ +source/ grub2/+ bug/1450783
https:/