It takes less pressure to engrave a plated bullet into the rifling than it does a jacketed bullet. According to QuickLoad, about 1,500psi less. Lower starting pressure means lower peak pressure, about 3,000psi lower using 124gr bullets and Power Pistol in 9mm.
So, working your load up to the max listed in official data is entirely safe.
HOWEVER, "velocity chasing" is not safe. You can't just assume that because the book got 966fps you can too, so you just keep increasing the charge until you get there. Obviously these loads are no where near max, but you get the idea.
In your specific example, I wouldn't see the slightest problem with adding 0.1gr more powder.
Using Ranier bullets at 1.120, QuickLoad thinks 3.8gr Bullseye would give you 959fps at 18,902psi while 3.9gr would give you 980fps at 19,919psi. Obviously far below both max speed for the bullets and max pressure for 9mm.
Still happily answering to the call-sign Peetza.
The problem, as you so eloquently put it, is choice.
He is no fool who gives what he can not keep to gain what he can not lose.
-Jim Eliott, paraphrasing Philip Henry.