I assume that what you call a BIOS boot order shortcut key is what my Asus MB call the BBS Popup Menu (F8). I really don't know, but I would have thought that any system that had multiple drive capability would have some kind of shortcut key.
Actually, I rarely use the shortcut key, because I don't switch OSs all that often, and find it easier to just change the Boot Priority in the BIOS settings.
EDIT: The main reason that I use this method is not so much for simplicity, it's because I don't trust boot loaders. Too often, the boot loader would become corrupt, and I would lose access to all of my OS at the same time.