Because data comes from experiments.
Unless we figure out how to create a black hole in the lab (spoiler, you wouldn't want to) or could get close to a natural black hole (spoiler, you wouldn't want to) you're not going to get any data for this.
Unless we figure out how to create a black hole in the lab (spoiler, you wouldn't want to) or could get close to a natural black hole (spoiler, you wouldn't want to) you're not going to get any data for this.
Current understanding is that there is nothing dangerous about creating black hole in the lab: it’s going to be so small that it will evaporate quickly, and event horizon is so small that it will be very unlikely to capture new matter.
I.e., if a tiny black hole had formed at LLC and swallowed the Earth, that would have been data.
Recall all the arguments quoting rates of Hawking Radiation from small black holes as if it were proven fact.
The point is that tiny black hole, man-made or from the outer space, can't swallow Earth in any reasonable amount of time: when it's gravitationally captured and orbits through Earth internals "forever", it's event horizon is so small, that it's very rarely interacts and captures new matter (after all, matter is not "dense" on the atomic level), so it grows very very slowly, even if it doesn't evaporate at all.
Any light black hole has really minuscule size. For comparison: black hole of mass of Earth is couple centimeters in diameter. Now, if such black hole comes from outer space and hits Earth, almost nothing will be left.
Microscopic black holes are an entire extra level of speculation over any other gravitational effects. Even in GR, black holes are not exactly consistent with the theory - they are singularities, indicating that (even if we knew nothing of QM) GR can't be a complete theory of nature.
So, discussing what microscopic black holes can or can't do is not much more than discussing what effect photon torpedoes would have on a Holtzman shield (Star Trek x Dune fanfic).
Because the smaller the blackhole is the faster it evaporates, below a certain energy the blackhole would turn all the energy/mass that was put into it into energy close to instantly, i.e. it basically turns into a bomb.