[JohnKSa]

Speaking only for myself, enough effort is when I'm satisfied that I can have complete confidence with the gun in my hand and not care what it is - without a thought.

Let's take a step back because I see where the disconnect is.

How do you define being proficient with a gun? What gives you complete confidence with a gun? I would define it as being able to do, at the least, all of the following:

• The ability to rapidly draw from my normal carry position (including dealing with concealment garments) and fire multiple shots rapidly and accurately at multiple targets and reasonable self-defense ranges while moving and making use of cover. That includes constructively dealing with any safeties on the gun--manual levers/buttons/grip safeties, etc.
• The ability to shoot with either hand and from retention positions.
• The ability to clear any type of malfunction rapidly and effectively while keeping eyes on the target.
• The ability to reload rapidly while keeping eyes on the target.
• The ability to safe and reholster the gun while keeping eyes on the target/surroundings.

Achieving that level of unconscious competency with a pistol is not a simple task, it's not something that can be done quickly, nor is it a level of competency that is lasting. If you stop practicing or don't practice enough, those skills will degrade. I don't know many people who have the resources (time, money, etc.) to truly achieve and maintain this level of skill with a single platform, let alone with many platforms.

Not getting good with various types can be a handicap.
And I'd druther not be handicapped.

You're focusing on only one aspect of this topic, and it's on the aspect that is the least likely for you to encounter.

Not being fully proficient with your carry platform is a handicap. Moreover, since the odds are tremendously in favor your being required to use your carry platform as opposed to a scavenged gun, that's a handicap that is actually likely to have an impact on any of your future deadly force encounters.

Not being fully proficient with all platforms is a handicap, but the reality of deadly force encounters is heavily in favor of this not actually being a factor since the vast majority of deadly force encounters are not resolved by the defender using a scavenged gun.

The reality is, that unless you have an unusual level of dedication, and an unusual amount of time and money to spend practicing, you will not be able to achieve unconscious competence with all the possible platforms you might encounter. So you will have a handicap--by dividing your practice resources, you'll handicap yourself by not achieving the level of competence you could have with your primary carry gun. And that's a handicap that could really matter.