On platforms that allow overcommitment, you can guarantee your commit charge is physically backed by writing to each page in a memory pool at allocation time (probably at application startup, or at the end of the main loop), then allocating out of that pool.
Using memory that's been allocated but not committed seems like a recipe for disaster.
They'll be pumping neutral gas (probably N2 or argon) to purge the borehole. I would expect the ablated material to resolidify as fine particulate, which would get carried to the surface at ambient temperature and trapped in a filter.
A 20km borehole with a 10cm diameter is only ~157m3 of rock. If the dig takes four weeks (which would be unprecedentedly fast), you only need to purge ~64cm3/s, which is pretty trivial.
They'll need to do something like mix the dust into concrete. Silicate dust is a respiratory hazard. But that doesn't strike me as a significant hurdle.
Global energy production in 2019 across all sectors was ~18TW. Excess radiative forcing from anthropogenic greenhouse gas emissions was ~560TW.
So we have room to ~20x our energy consumption before we start having to worry about climate change from direct heating, so long as we draw down the excess CO2 we've emitted.
Wind doesn't contribute to that total, as it's harvesting energy already in the system. Solar mostly doesn't contribute to that total, but it does increase surface albedo.
Using memory that's been allocated but not committed seems like a recipe for disaster.