I feel it should be easy to dismiss this. If there's astrophysical sources of postulated superheavy elements, they wouldn't have fractionated between planets and asteroids so cleanly: there'd be substantial amounts of them in the Earth's crust and mass spectrometry would have found them instantly. (Or a population of objects would have collided into Earth later, or whatever). We're talking quadrillions of tons in just this one asteroid [0]. That's incredible quantities of material to be undetectable on Earth. What's the proposed explanation for that?

[0] https://en.wikipedia.org/wiki/33_Polyhymnia