a command you can invoke that changes the private key?
I asked a related question, in relation to the language people use when talking about hpool, a while back:
The consensus is that, at least right now, there’s no “re-keying” of plots. I suspect that it may be be technically possible, based on my (limited!) understanding of what plots are, and how public-key crypto works. Though I’m not sure it could be done without sharing secrets.
But even if it is possible, I’d assume the data are the same (or maybe more precisely “equivalent”) in both the original and (theoretical) re-keyed plot – meaning it doesn’t get you any protection against double-farming.