I have used those nylon knife pouches that are found at flea markets and gun show junk boxes.
They have so many different sizes you can always find one to fit whatever.
They are not at all fast, but they keep the magazine clean and protected. This works extremely well for the spare mags carried in your vehicle as well as pocket when belt carry is not appropriate.

You know that might very well be my only option.
Some kind of
Generic "tactical" sheath that covers the metal up to the butt cap.

$2.19 light or pepper spray or tool holder.

Right now I am trying to locate someone with a three D printer in my general vicinity.

I thought those things and drones were going to be the next frisbee or hula hoop.
Not so much ,it seems.

Thanks for the suggestion.

bendable, enough people are "custom bending" Kydex that I wonder if you can't have something made locally that will suit your needs.

For what it's worth, I'm not aware of anyone else making relatively hard plastic sheaths for magazines. Then again, I've been relying on nylon (Galati and others) for the purpose for years.

I thought a bunch of people were sculpting kydex for all kinds of stuff also.

After calling 7 gun stores ,nobody could recommend a person in our general proximity for that either.

Once again , leave it too me to find a reason for something that nobody else gives two hoots about.

( My life story)