If the course of fire requires you to start hammer down and weak hand only I very much notice it, if the first shot is particularly challenging I'm aware of it and try to place extra focus on a tight grip and smooth pull. Regardless of the gun a tough first shot requires a little extra focus on getting the gun stable after the draw, for me anyway. Both situations are somewhat rare.
The transition from 1st shot to subsequent shots I don't notice at all, I think it is like the transition from first shot with finger starting outside the trigger guard to second shot with all guns, it just happens.