[colanderman]

The asymmetry is compensated thusly: when you feather your paddle, you should grip in only with your dominant hand. It should rotate freely in your non-dominant hand.

Your wrist movements can then be symmetric -- your non-dominant wrist is free to move as you please.

And because you are free to set the feather as desired -- you can set it in such a way to minimize the rotation required of your dominant hand (and, per the above, non-dominant hand) to transition from one half of the stroke to the other.