GRUB complicated, Nah!

If you are using an MBR formatted disk it should be quite easy to tame
down GRUB. What I do is keep it tied in a locked cage where it cannot
do any harm! Just use a dedicated partition for GRUB. In it install a
very minimal Debian or whatever Linux OS, boot it, install GRUB so
that you can boot, do an update grub or what is relevant to the
version you are using and exit. That way you separate the bootloader
from the other operating systems on the same disk or computer. To
avoid having to boot the GRUB installation whenever a kernel is
upgraded use the root vmlinuz and initrd.img symlinks in grub.cfg.

The above is what I do, and I have a really complicated setup with
multiple OSs installed on the same disk. Never had trouble with this
setup although I have been using it before the advent of GRUB2.

I have the Linux-Allergic HP Probook 4540s laptop and still can boot
it with the setup described above. I don't want GRUB messing its menu
every time there is an update to it. Therefore, I manually edit
grub.cfg to get exactly what I want.

No shell scripting from hell will stop me from manually editing my
bootloader so that I tame it to display text exactly how I want it and
in the pricise order I need.