We love installing Grover Sta-Tite Tuners. Quality is easy to see. Even the supplied Phillips head screws are top quality.
If your neck is receiving replacement tuners, we fill all screw holes -- OEM and others -- before installing the tuners.
We use matching mahogany (Sovereign and Martin) or maple (Gibson) pegs to fill every hole. We never use filler. This is important if the screws are to go in straight. For example, if a maple or birch peg is glued into a Mahogany gear head, the screws won't install at 90 degrees to the face, because the maple forces the screws to install to one side. Maple is much harder than mahogany.
The image shows one of our hand made screw hole filler rods. This one is scrap from a smashed Martin D-1 back.
In the image below, the gear head back is refinished. You can’t see the old holes at all. New holes were just drilled. Your guitar may not have a refinished neck, but under the new tuner plates, all holes are filled before drilling new ones.