According to the manual, the only difference between the HC zones and the rest is that the former have an inrush limiter. From the manual:
“Zones D and E on the Power Plant 10 are marked “HC” for High Current. These zones are identical to Zones A, B, and C in terms of the quality of regenerated, regulated AC output, however also enjoy the benefits of an in-rush limiter. When capacitors or tubes are powered down for extended periods, they drain of their capacitance. Upon powering these devices up, they can demand a lot of current to both turn the unit on and to reintroduce this capacitance. The result in one’s home can, with very high-wattage-draw devices, go so far as to trip the circuit breaker in the residence. An in-rush limiter, such as the one found on Zones D and E of your Power Plant 10, slows the pace of initial AC output. A more gradual rise in output voltage allows the connected device to power up fully while not over-taxing either the P10 nor the mains power.”
Depending on your amps that may or may not be important. Once the amps are powered up, it shouldn’t matter whether they are plugged into an HC or regular outlet.