With a foundation of continuing revelation, I believe there is relatively little "immutable orthodoxy" when it comes to Mormon doctrine.
Perhaps there is Smithodoxy (Joseph and Joseph Fielding), Prattodoxy (particularly Parley P.), Youngodoxy, Talmageodoxy, McConkiodoxy (makes me laugh just pronouncing it as I type), Nibleyodoxy, Hinckleyodoxy, etc. - but there is almost no orthodoxy on which all "good Mormons" will agree. Things change too much to pin down almost anything as orthodoxy, unless it is defined specifically as what is taught generally at a particular time or by a particular person.
I LOVE THAT; it flummoxes others; it really, really torques off some.