I believe I have seen tuners advertised which will switch between equal and well tempered, the other one with the name I can't remember, and natural pitch as well. I don't know if anyone has yet made one for the new fangled patented (I'm not joking) tuning which involves a non-straight nut and offsets in the string pitches to roduce sweeter chords in all positions. Mine doesn't have any such features and I'm not sure I'm good enough to need them. To my ear guitarists who use harmonic tunings tend not to tune to true equal temperamant anyway.