Comment # 3 on bug 1101756 from Neil Rickert

>This bug is about not needing to do so ...

Yes.  But that's hopeless.  Too much depends on the firmware.

On the box that I referred to above, the firmware changes the boot order unless
I go into firmware settings and set the order there.  And if I delete a UEFI
boot entry, the firmware puts it back unless I also delete the associated
".efi" files.

What I do is use "/etc/grub.d/40_custom" to make sure that every system can
boot every other system.  I usually do this via a grub "configfile" command, so
it just uses the native grub configuration for that other system.

>Choosing 2 or 5 from the BIOS UEFI menu produces only a grub> prompt.

You should be able to change what happens for 2 (the UEFI OS entry).  That just
boots with "\EFI\Boot\bootx64.efi".  So copy to the boot files from your
preferred system to "\EFI\Boot" in the EFI partition.

When you install openSUSE, it will put its boot files there if it sees that no
other system is using that directory.  Otherwise openSUSE doesn't touch it. 
However, Ubuntu, deepin and Solus all ignore what is there and put there own
boot files there regardless.

What it amounts to, is that UEFI is a mess.  There's no consistency between
vendors or between operating systems.