You can go through every scenario that you can think of, and train for those scenarios where you have the perfect outcome. The perfect response. The perfect response time. Fact of the matter is: there is NO perfect scenario.......or the perfect scenario is RARE. Example: the Indiana mall shooting. Young man, had some basic training, learned how to shoot at distances, had the choice between him and his girlfriend leaving, or him engaging the shooter. At 40 yards, plenty of time to make that decision. A rare scenario.
We can argue and debate about safety versus no safety 'til the cows come home. If it comes down to saving a second, or saving a few seconds due to momentary brain freeze, wouldn't it be just as "efficient" and time saving to have your finger on the trigger as you draw? Saves time between putting the trigger finger on the side of the gun as you draw, assessing the situation, and putting your finger on the trigger. What if you are jumped, fight free, are cornered, and have to draw and fire? Will your finger automatically go to the trigger on the draw, or will there be that split second delay between draw, insert finger, pull trigger? Now, add a safety into that scenario.
Yes, it does come down to training, for "muscle memory" or "automatic trained response". We mainly try to train ourselves not only on the proper, safe, fast, and efficient use of our firearm, but to train our mind, reflexes and response to any "given" scenario. We are trying to train our brains to go automatically to the "fight or flight" response and bypass the "brain freeze" that happens when our brains are overloaded with the sudden and violent environment we find ourselves in at that moment. Of course, in the REAL world, that "perfect" scenario that we train for is rare. This is why we always have to have "situational awareness" and our "heads on a swivel". By having our radar always on, we can hopefully be prepared for a situation and response to that situation. Within this scenario, we are better able to make those judgements on our response and be prepared to execute our response. Whether it is "flight" for us and our loved ones, or "fight" if all reasonable avenues and routes are exhausted.
So, in my opinion, it is our training in situational awareness that is key to this whole thing. How to avoid a situation or possible confrontation is the first critical step. De-escalation if confrontation is unavoidable. Our response based on how confrontation goes. We all know the drill. It is our alertness that dictates how we respond. If we are aware of what is going on around us, and find ourselves in that situation where we have to draw our firearm, we have already had the time to make that decision. Which means we have the time to calmly go through the steps in our training checklist, such as disengaging the safety on the draw. However, since they say most self-defense shootings happen within 21 feet, 85% of the shootings, we must train for that. Meaning a quick draw and fire. How much time is added by removing the safety, and how much time is wasted transitioning from finger on side to trigger? Will it be automatic, or will it take a nanosecond? Will your finger automatically go to the trigger in that situation? Will you have your mind sufficiently trained to make that split second transition and judgement? Every single "safety" that we have, whether it is a manual, a grip safety or combination of both, a trigger safety, and automatically keeping our finger off the trigger on the draw are all considered "impediments" in a full on, shtf situation, and could mean the difference between life and death.
It comes down to our situational awareness and preparation in the event that things go sideways. We can train for any given situation. But those situations and scenarios are not guaranteed to turn out how we envision them. As a matter of fact, with rare exceptions, they won't. Be aware. Train your mind, body and soul for when bad things happen to good people. Knowing your firearm and how to automatically handle it in a stressful situation is vital. But it is only a part of the whole. You being the whole.
Sorry for the long winded post.