Just a word of caution if you plan on doing any wet sanding as pre-drilled holes can easily absorb water and swell the timber hence why I always drill last when attaching all the hardware.
A valid point.

However I avoid the swelling issue by rubbing a small amount of bee's wax into the holes before I start the wet sanding process.
It doesn't require much and the small amount that may smear around the outside of hole will wipe off with bit of rag dampened with metho.

Once the wet sanding and polishing is done, the wax can be extracted with a toothpick. Any residual wax inside the hole makes a great lubricant when the screws go in.