It's a total dumpster fire support nightmare. Glock has MILLIONS of guns in circulation.
Also its a bad look "Oh you need to replace your magazine catch now on 9 billion guns, the one we shipped with the gun sucks and doesnt work with the
new mags we make". Yeah, I'm sure the execs at glock are lining up for that one.
In a Glock 19, "No It's not" (Tucker Carlson voice)
Look at a G19 mag, it's n ever happening without extending the mag. The G19 is already the most efficient gun in its class, and there are very few other guns that even
come close. Look at the CZ-P10 and the Caracal-C (not produced right now). Those were both native 15 round guns, with metal mags. Anything that can actually compete
with a G19 is either the same capacity or very close.
Protip: There are already metal G19 mags on the market, made years ago, by USA or whoever. They don't hold any more than a regular G19 mag does. Remember theres also f***ery
going on with how the ammo advances into the top of the feed tower of the mag, too. You can't mess with that too much, or the gun stops working. There is a law of diminishing returns
with regards to how you can stack ammo in a double stack magazine.
Do you really think someone hasn't thought of this before? Really?
The only reason it happened with the 43X/48 is because there was actually a design inefficiency there that was capitalized on. It's not really viable on other guns in the platform. Otherwise Shield Arms or whoever would have done it already. They haven't because it's not feasible.