I don't know of a custom maker installing a mechanical latch. I have formed Kydex molded to where you have to really want the gun to draw it. Safariland has the best regarded retention holster. You would have to search for your gun.
My Kydex benders use heat. Typically a small oven and a heat gun. Not a lot of heat, their inert models and a lot of the real guns are themselves plastic.
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