I have two suggestions:
- on UEFI systems, would it be possible to use an EFI variable to force grub menu? That
way, it would be possible to enter the menu from UEFI boot loader or shell, even if the
system itself is in non-working state or on read-only device.
- this one is on the polish side of things: on UEFI system, when GRUB isn't going to
display anything, it should not set the text mode or clear the screen. Currently, when
UEFI runs the bootloader, it does it with graphic framebuffer. GRUB then switches to text
mode, when quiet it does nothing just displays the blinking cursor at the mid-bottom of
the screen and then the kernel takes over and switches back to graphic mode. The user gets
two ugly flashes as the modes change. Windows doesn't set or clear the framebuffer, it
displays its progress indicator on top of whatever was left by firmware there (mostly
computer manufacturer logo).