Life is not the movies.
How fast a knife deploys has not one wit of consequences when it comes to the knife being used as a weapon.
Most people who are going to harm you with a knife, have had it drawn and hidden for a period of time before they attack. If you are under attack, you are pretty focused on not being injured by your attackers weapon.
If you do any force on force drills, and knife draws under stress you find out some pretty important things. Case in point, a time ago, I was training with some folks, and doing just this. I was being beat with boxing gloves and pads, I had to break contact and draw the knife. It was a waved Emerson Commander trainer. I broke contact, drew the knife and in the process tossed it across the room.
Knife duels as you engaged in, are an unheard of reality on the street.
The message that needs to be out there, is that a knife that opens quickly is no more dangerous than a knife that takes too hands to open. It is not hardware that wins fights, it is software.
I have come to dislike the wave. It works when you don't want it to, and it does not work when you need it to. I won't kick a waved knife out of bed, but I also don't need to have a waved knife to feel complete.