Slap me down if I am wrong here, but as regard starting with these power grips... and do bear in mind I have not used them.

But pwergrips are something you can fit to flat pedals... yes?

So.. that being the case, when stopped and your foot is off the pedal, the weight of the powergrip will turn the pedal so that the side without the powergrip is upper most.. in short... a normal flat pedal?

So you set off from the lights... and only when you are moving use your toe end to flip the pedal and slip into the grip? So it should be no harder to start to pedal than a flat... and when safe you slip into the grip?