I've always sat the crown race in the vice, not clamped just resting on the edge and then tapped the steerer with a dead blow hammer or mallet, yet to have a problem removing one.
Go easy with that! It's very easy to crush the top of the steerer and knacker the threads.
I use a crown race remover which I tighten ap and then hit the corners of that with a hammer. Unless the race is a very loose fit there's still always a little collateral to the top of the crown though