Great post and question.
I imagine many others here would be much more eloquent and know best terminology.
Guess I can only play “devil’s advocate”, but mainly to help protect you and others.
Aiming for anything other than the chest center mass poses higher risk of you missing altogether, that round then has higher chance to hit an innocent.
You never know where the bullet will move to within the body. You also might not even know if you struck or “where” you struck, especially if the perpetrator is wearing layers, dark clothing, or if it’s dark out.
If there is more than one assailant, you might need ammunition and might not have the luxury to pick and choose where you try to hit. Aiming for the chest center mass increases your chances that you’re bound to make contact. If you miss, then the assailant has a chance to hurt you.
You’d be under such duress, accuracy is compromised, hence center mass might be more feasible.
Think of all the paper targets at the ranges, notice center or highest score is 10, in the middle; and in CCL permit range tests, they prefer closer to the body/center. Why is that?
That’s why President Biden got “raked through the coals” for asking Americans to aim for a leg.
Exceptions: Your life is at risk, and at the very same time – only another body part of the assailant is within view. Exception, chest body armor.
I think deeper than what body part you’re aiming for is asking yourself and talking about why you’d rather hit the pelvis than the chest. What are your fears or concern, why. As those are legitimate.
Remember, he/she is pointing a loaded gun at you, your life is about to end. If you’re afraid of meeting lethal force with lethal force, then that’s Ok, it’s your right. There are other non lethal force options available, but it’s your right to go non lethal. Lethal is not for all in defense.
I’m for responsible persons to own and carry, but learn safety. I worry when I hear anyone aiming for anything else but the chest. You only have one second to make one decision.
I imagine others have contemplated your same valid points. It shows you care and are looking for best practice. It’s complex and unique to our nation.
I edited and revised my reply, trying to shorten it too.