A dedicated defensive carry weapon, right? Not a dedicated competition pistol?
Leave it stock. Spend the time, effort and money on making "improvements" to the shooter.
(Yes, as a Glock armorer I'm going to go with the "leave it stock" option.
)
Ever heard the Risk Management philosophy of "Predictable is Preventable", though?
Why needlessly create unnecessary exposure to potential liability, and any difficulty of explaining non-factory modifications, in any sort of legal proceeding? Got extra money to burn in legal fees, or too much in the way of assets & property you might not mind losing?
If Glock currently requires a letterhead signature of the appointing authority (Chief, Sheriff, etc) in order for an agency armorer to receive their "-" connector, maybe it would create a needlessly uphill effort to explain why any individual owner/user would know better than the gun company about how heavy (or light) the triggers ought to be in their guns used for defensive/service carry?
Interestingly enough, in my last armorer recert class it was mentioned that the company had either started, or was going to start, requiring a letterhead waiver if an agency decided to buy G34/35's, with their lighter weight triggers, for use as duty weapons. First I'd heard of that, if indeed it's their current policy or practice, but I could see their point from the company's perspective.
Besides, "improve the trigger" on
one Glock, and that's all you get. Improve the skills and trigger technique of the
user, however, and
that can be applied to
other Glocks.
Just my thoughts. (My own 3 Glocks have stock triggers, BTW).