Paul,
I wrap main sheet around my hand several times & just flick off the required loops when throwing sheet. Personally i think you just need to be mindfull of this fact & be ready to flick instantly.?
On the longer races, I find the wrapping tends to get painful & then reset a suitable position & number of wraps around the hand. Just my 2 cents worth.
Who told you to never wrap around your hand.?
I've been told by some people that wrapping crushes your hands and can do damage. I do wrap somethimes (usually when tired) and it does hurt after a while.