I read the whole pitch deck and it seems like you've thought it through well. I'm curious about the potential for failure; if one of the last links freezes up somehow (i.e. the disengagement you mention elsewhere fails), is there a process for clearing it?

The single shaft vs multiple parallel approach does seem a bit risky in the early days. If there's a 10% failure rate, and you built one shaft, that's a 10% chance of an existential threat to the company. 10 shorter shafts mean one will likely be inoperable.

Of course over the long term worrying about this doesn't make sense. Once you've scaled, 1k large vs 10k small shafts would not matter from this perspective.

Best of luck mate!