If you can find one, get a Recoil Spring Assembly and install it. Get the Glock cheap looking plastic one. "Higher End" RSA's come with frequent problems, and when someone has a problem with a modded Glock, the answer to the problem, every single time is return it to stock, or have someone who knows what they are doing return it. They are funny about some "upgrades".
These springs are difficult to impossible to gauge how the life is on them, and when I change one, I can tell the difference in the pistol. One of those, didn't know there was a problem until there wasn't moments. For a $10 part that has a mediocre wear life that is user friendly to replace, it is a no brainier.
You keep saying it is "well broken in" and not knowing exactly what that is, one would think some round count is in there. Glocks are "Broke In" out of the box for functions.Trigger parts wear in and the loose nut pulling it gets worn in as well over the course of the first thousand rounds or so. It should be held like you are mad at it and it's trying to get away.
Otherwise, trigger time for the wife unit is the easiest and cheapest answer. These days, that answer isn't cheap.
Happy researching