I like the idea of Dual PSU, especially for expansion and failover
A Seasonic PSU would be the last thing to fail in this or any miner. I can almost guarantee you that HF aren't using two for failover purposes.
Correct, we're not using two for failover purposes, we're using two because we chose to provide a 20% safety margin on top of what the Sierra might need.
You say "20% safety margin" and I think "20% overclocking margin."
i highly doubt they are going to take half of the psu's out just before delivery to save money.
