While larger engines may have a gearbox to reduce the prop rpm (and thus tip speed), the gears are a fixed ratio (generally between 0.40 and 0.75) and can be ignored when studying the governor operation.
The biggest effect of the governor can be felt whenever the IAS is changing. If you set e.g. 2400 rpm at start of TO roll, and keep the nose down and let the aircraft accelerate to whatever its max IAS may be, the engine will still be turning 2400 rpm. Similarly during aerobatics.
Another note - the tachometer on the panel shows ENGINE rpm; if a geared engine, the prop rpm will be slower than the tach reading.