Geoff,I disagree. I have tuned enough 2 string pianos, and for that matter enough strip muted pianos that demonstrated that two or three strings generate a more complex and rich tone (except for the low bass, which is complex enough with one). One string produces a thinner and more pure tone with is different enough to generate interest among artists. There are also no unisons to go out of tune, so the tuning is different and perhaps somewhat more stable.
But its just a point of view, for me, the artists playing and the audience listening.
You can't be too thin, too rich, or have too many microphones! And here I always thought it was too many clamps.
Great and interesting sound.