Maybe you are aware of the scope involved.
There is no single end of the line for cars to park at. It's going to be 50+ miles of tunnel with something like 100+ cars and 50+ stations.
There isn't room or electricity in the current station design for superchargers. They've already spent millions building 4 stations with no superchargers or even destination chargers in them so clearly they aren't going to retrofit any in those locations. What makes you think they'll add them to future stations?
Don't you think that your arm chair quarterbacking is suggesting something the Boring Company already considered?
Notice how there is no charging location or master station for cars to sit at when not in use?
As far as I know it the current process is they take them to a public supercharger each day and will continue to do that going forward.
There are 7 Superchargers in Vegas very close to the loop.
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