I am in the process of making a diagnose & manteinance Debian setup onto a
USB stick that can boot in whatever PC drops in my hands. Working on
having a custom EFI boot entry I encountered that adding the --bootloade-id
option in grub-install makes the system boot into the GRUB console
instead of the usual GRUB menu. Not GRUB rescue, the regular GRUB
console.

I can get in there by manually bring it
up with the following GRUB commands:

set prefix=(hd1,gpt3)/boot #or whenever /boot/grub resides
insmod normal
normal

I tried almost all combinations of adding --recheck, --no-nvram and
--removable, but it seems that it the route isn't EFI/debian or EFI/BOOT
the system won't boot on the menu.

Weird enought I copied grub.cfg into EFI/[custom-name] and it seems to
work, but the frame of the menu is compsided of the unknown square
unicode character

Currently testing on a MacBook Pro 9,2, did some test on a brand-new
Lenovo L340