I think its important to note that the cut chart you posted was from a Hypertherm, not a Razorweld. I was trying to figure out why it was different from the official Razorweld cut chart, and then saw your Service Manual link was to the Hypertherm.
From my limited 2-years experience with the RW45, it seems to enjoy sitting between 110 and 120 volts. Whenever I turn SMART control off, i just use 120v.