This is “Premise B” of the LSAG safety case: the fallback that makes the safety conclusion independent of Hawking-radiation theory. Its logical structure is a dichotomy over the crossover radius R_C at which gravity becomes four-dimensional: (a) if R_C <~ 200 Angstrom, accretion in Earth is slower than the solar lifetime by direct calculation; (b) if R_C >~ 15-200 Angstrom, accretion would also destroy white dwarfs (and for D>=8, neutron stars) far faster than their observed >~ Gyr ages — contradicting observation — so such configurations cannot be realized. The paper’s supporting layers: charged stable holes are already excluded by Earth/Sun survival; neutral ones by the white-dwarf and neutron-star bounds.