Comment # 9 on bug 939453 from Chris Murphy

(In reply to Michael Chang from comment #2)
> The problem is that not all users like the idea to write grub/grub2 to LBA0.

Then they should opt out and use extlinux instead of GRUB 2. The current
openSUSE behavior and recommendation is incongruent with GRUB upstream.

http://lists.gnu.org/archive/html/grub-devel/2015-08/msg00093.html

Basically what you have in openSUSE now is something that's a.) inconsistent
with GRUB upstream b.) inconsistent with all other distros c.) not documented
anywhere a user could find it d.) not a self-describing or easily followed boot
process, e.) installing GRUB core.img into the Btrfs 64KiB bootloader pad while
supported is considered suboptimal by GRUB upstream they prefer it going either
in the MBR gap or BIOS Boot where there's more room for a larger core.img.

This makes it difficult to troubleshoot, the user has to get this esoteric
information from not just the openSUSE community since no one else does it this
way, but a narrow slice within the openSUSE community because it's such
esoteric (and unexpected) behavior.

If GRUB by default, then only support their recommended methods. Optionally
provide UI for the user to opt out of overwriting LBA 0, which then uses
extlinux, which is explicitly meant for this use case.