The “keeping both hands in plain sight” is just a good idea, whether it is the law in your area, or not. My philosophy, which I practice, and have taught my boys, is to do everything possible to keep any LEO you contact “at ease”. Veiled threats, lack of cooperation, and disrespect are mostly for chumps who like to chew on sod while being cuffed...
An officer who feels safe is a happy officer. A happy officer is much more likely to give you a warning, rather than a ticket.
Things that make an officer feel unsafe are standing out in traffic, weapons, and furtive movements. You make the officer happy, and he’ll make you happy.
Save the debates about the righteousness of traffic stops for a time when you are not stuck out on the side of the road with an officers ticket book in his hand.