Okay, a number of views on this.

As a gunsmith, as an instructor, as an ex cop, as a person who’s carried for 25+ years now.

From the instructors view, carry what you practice with. Too many practice and come to classes with a full size gun then carry a mouse gun that they can’t operate under stress. Better to carry the larger gun you actually use.
Second part of this, that pocket gun isn’t going to be where your normal holster is, you’re gonna reach for something that isn’t there.
There’s a reason cops are told to carry off duty in the same place as their duty gun, their brain is trained to go there first.

As a gunsmith, I can build what you want, just leave the check blank.

As the ex cop, “why the %&×$” didn’t you use something larger?”
You just put three rounds into bubba-j and now he’s pissed. And now I gotta go deal with him, wonderful.
Sorry but the cops would rather clean up after a shooting by calling the coroner and investigating the shooting rather than arresting the scumbag, taking him to the hospital on the taxpayers dime, then jail, court, then see him released because he’s always been a nice boy who was straightening his life out. I don’t care what the PC comments are, that’s the reality. And that poor bad guy, who suddenly can’t work because he’s maimed for life, is gonna sue you for a pile of cash, and your insurance company may just pay it out to save time.
And why wouldn’t you carry the most effective gun you can?
Having shot a number of things, been a part of a number of autopsies, been privileged to read a number of shooting reports and coroners reports, I will not carry less than a 9mm.

I had the displeasure of having to dispose of a number of aggressive dogs over the years, the first I used my backup .380 on. My Sergeant was giving me grief over my shooting until he saw the 6 holes in the off side of its chest. The next shift, I had switched to a compact .45 as backup and never changed from that. I carried a number of third guns, for testing and animal disposal, I got to shoot a lot of road injured animals, and I found out what worked and what didn’t on live critters.

Putting all that together, as well as all the years of concealed carry, I prefer a mid size gun for everything but pocket carry (when I can’t carry a real gun).
My minimum is a 9mm, preferably with a 10+ round magazine.
Very simple, bad guys generally aren’t alone anymore. If it takes 5 to put down bad guy number 1, and I’m carrying a 5 shot snubby, bad guy 2 is gonna have my lunch.
Second, if I’m not carrying a reload, if I left it in the car, I want as many bbs as I can carry with me.

Edit to follow.