Holding prius at a stop using accelerator harmful to HSD?

Not sure of a simpler way to put this question and was unable to find an answer through google search.
This would apply to any toyota with HSD i assume but since i drive a prius v this is where i will post my query.
Sometimes in traffic i will come to a stop while climbing up a hill. I notice the Prius can hold its position on an incline just by holding the right pressure on the gas pedal without putting foot on the brake, no noise, no fuss from the ICE of course because its not running. Other times if the grade is just right i can release both gas and brake and the simulated "creep" mode in the HSD will keep the car stationary on the incline.
What i'm wondering is does this cause any extra wear/harm to the HSD? since load is being applied to the electric motor to keep the car stationary is it simply causing more draw on the battery versus just holding the brake down or would it also put extra stress on the electric motors?

 

Yes I have used hill start assist on occasion if its especially steep to avoid rolling back but usually i can be quick enough to go from brake to acceleration not to have to engage HSA.
As to loading the HSD to remain stationary on a hill I never did this either on my standard ICE vehicles as i'm quite certain it would cause extra wear on the clutch(manual)/torque converter?(auto).
Its really a matter of laziness I suppose, easier to control my forward movement with foot on the accelerator pedal than to switch from brake to accelerator when crawling along in traffic.

 

Is that why the high pitch whistle of the inverter stops if i push down on the brake pedal hard enough? If i have just light pressure on the brake(enough to keep the car from moving) it whines/whistles a bit, making me think power is not disconnected unless you push hard on the brake?