unable to persist bootloader id

Rather than override it on the command line to grub-install, you should customize GRUB_DISTRIBUTOR in /etc/default/grub.

I had initially tried changing the value of GRUB_DISTRIBUTOR, however grub-update does not take this value as the bootloader id.

If you notice the default GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian` produces "Ubuntu", however the default bootloader id is "ubuntu".

It seems grub-install truncates the distributor at the first whitespace and converts it to all lower case. I'm not sure why this is, but it doesn't feel right. Maybe Collin can shed some light on it.

grub-install, at least on 14.04 and 15.04, seems to hardcode the path "EFI/ubuntu" into all secureboot images. This has the effect that regardless of the boot entry that is selected in the EFI interface, grub always reads (ESP)/EFI/ubuntu/grub.cfg and continues to boot from the volume referenced there.

The binary /EFI/<bootloader-id>/grubx64.efi always contains the hardcoded string "EFI/ubuntu", which seems to be covered by canonical's signature and thus unchangeable.

If secure boot is deactivated, editing the grubx64.efi binary to reflect the correct path fixes the issue for me; i.e. if the bootloader is in EFI/mysecondubuntu, change EFI/ubunt2/grubx64.efi so that the string "EFI/ubuntu" becomes "EFI/ubunt2" (better keep the length the same in order to not break the binary alignment). This only works with secure boot disabled in the firmware; otherwise the signature becomes invalid.

However, when grub-install is invoked using --no-uefi-secure-boot, it gets even more confusing: grubx64.efi doesn't contain the hardcoded string anymore, but it seems as if grub.cfg is not even considered anymore – grub directly continues to boot from some hardcoded boot volume which I am unable to modify!

All of this makes it almost impossible to install two versions of Ubuntu on a single machine.

OMG....it this still an issue, so many years?
Using "--bootloader-id" doesn't work. Either remove the option or make it work!

grub-install --bootloader-id=customfoldername # <-- this is exactly what I wanted

it didn't work for me at first, but then I found this: https://askubuntu.com/questions/1129269/install-grub-using-custom-boot-loader-id-e-g-myubuntu - "... After running grub-install with --bootloader-id, run grub-install without any arguments. It will create an ubuntu entry. Delete it if you want to, but now your id is going to work "magically". Very annoying, seems to be an old bug. Hope I helps."