IMO the whole concept of terraforming is silly

planets can be lived on when they have a sufficient magnetic field, and at that size there is almost always oxygen and same air pressure and all the things

it's my opinion that asteroids eventually accumulate mass and become moons, and then accumulate mass and become planets, then grow through to the jupiter phase and then once they accumulate enough mass, the pressure and massive magnetic fields ignite plasma and they become stars, and the entire nonsense about black holes, they are not dead stars, they are just so big that light can't escape, and inside they are accumulating more and more mass

idk why anyone thinks that it can be anything else in light of einstein's formula, sure, inside the event horizon time is so slow that light is almost not in motion, but anyway

much more useful thoughts to have are about how you can make a spacecraft that you can actually live in full time without getting cancer, the key would have to be a superconductive magnetic field generator arrayed around the surface of the ship that deflects radiation and plasma

and you also need high bandwidth entanglement communications, how do you do that while also shielding yourself from most radiation, i guess it has to also include some kind of channel anyway that you safely allow radiation and high energy particles to pass through

living on these other planets is going to be the same problem, their magnetic field is induced and weak, radiation on mars and venus are going to be very high and without that shielding forget it

once you have the energy and the magnetic deflection technology it doesn't matter where you are, you can just fling out residential craft and then also travel in them

you have to find a habitable planet, you can't make a planet habitable without a massive amount of matter added to it so it is heavy enough to have a permanent, strong magnetic field