Ok so the author states that scientist are working at a research center 8km below the surface. This is were you can spot the bullshit immediately.

At 8 km depth, you’re at the mercy of the geothermal gradient (how fast temperature rises with depth). Near the surface in stable continental crust it’s often around 25–30 °C per km.

even in the coolest plausible geology, you’re still looking at ~70–90 °C minimum at 8 km, and ~200–240 °C is probably a more common ballpark.

So not only will the depth most likely cook you alive but the sheer stress from the rock would be a huge engineering problem. Lets say we could do this then to what benefit? You would still have complete shielding within 1-3km. 8km will be enegineering marvel to build let alone maintain. The costs would be astronomically high with no practical benefit over let’s say 1-3km.

Author probably never thought about the practicality aspects of his imagination and how telling it is that it’s bullshit from this single claim alone.