Its my experience that features like this, that sound like snake oil, really do come from some place where someone somewhere found this change sounds different (better to them at least). I think the theory is that you spend less time in the off mode with rectifier diodes and reduce dI/dt in the transformer, and other subtle changes. In effect I imagine this is intended to make the AC->DC power supply more efficient, lower impedance, something of that sort. I'll definitely set and get used to good 'ole 60Hz mode and then try multi wave later and report out.
As to the voltage drop, yes it is only on that one circuit. That 15A circuit drives a plasma tv, pio receiver (thankfully class D), misc source components, 2 ceiling fans, a few floodlights (all LED now), and then my listening room setup with a Rogue Atlas amp, BeePre, and various source components. I will try and improve the IR drop throughout that circuit by 1) replacing the 21 yr old circuit breaker that has been baking in the Arizona sun, and 2) coat the breaker contacts and all outlet and wire nut connections I can find with a thin layer of silver conduction paste.
And then of course I'll add the Bottlehead DAC to the mix when mine arrives... can't wait :-).
Mac mini running Roon->
Mytek Brooklyn DAC+->
Darwin Truth RCA IC->
BeePre (BeeQuiet, Mundorf Ag/Au/Oil, Sophia Royal Princess 300B)->
Audioquest Colorado->
Rogue Audio Atlas Magnum amp (Psvane small signal tubes, KT150s)->
Audioquest Gibraltar-speaker cables>
Magnepan 1.7 & REL T-5