I break edged weapon training into two areas, spontaneous edged weapon attack defense and using a knife to defend yourself. There are three parts to an attack, accessing, deployed and attacking. Knowing the preparatory movements required to draw a weapon are important. That can allow you to foul the draw and make it possible for you to never have to defend against the blade. Most robberies and things of that nature will have you facing a deployed weapon meaning the guy will only threaten and menace you with it. The knife being a contact distance weapon requires you to be within contact distance using your open hands or other tool to reach your attacker. If the knife is only deployed you have little to work with and will likely only result in you getting cut. Attacking is the BG actually trying to cut or stab you. In response to this-
Move off center
Try not to get cut
Get cut as little as possible
Control the weapon hand and do violence upon them until they are no longer a threat
Research shows that the last few wounds are the ones that prove fatal. This means that you need to do whatever it takes to end it as fast as possible. I believe that your initial response to a edged weapon attack is likely to be open handed. If at conversation distance you are lucky enough to draw a knife or pistol it will do little to stop the mechanism of the attack. Even worse because of ritualized combat you will be more likely to focus on your tool use and stay to the front instead of adhering to the first rule and moving off the center line.