I don’t see how that statement can be true? The SF trigger housing has material removed from its back side. Everything else about it is the same as a standard TH. The trigger bar, connector, trigger spring... All these are the same. Everything in the slide is the same. The distance to the FP safety and drop safety must also be the same. Everything in the frame, with the exception of the back side of the grip, is also the same.
Yes the overall distance, measuring from the back strap of the SF frame up to the forward portion of the trigger is shorter when compared to the standard frame. However, I can not see how the trigger pull can be any shorter when ALL the same parts are used in both guns.