I've gotten through the RV-14 tail feathers and most of the wing in the last 10 months. There are a few cases where the plans will say to final drill, but then it turns out it's not necessary. Most of the time if the plans say it, it is necessary.
Tip #1: The best way to tell if it is necessary is to insert an appropriate sized rivet into the hole. If it slides in easily, final-sizing isn't needed. If it goes in with trouble or doesn't go in, and you are sure the parts are well aligned, then you need to final-drill.
In this particular case, the skin holes may be final sized, but the trailing edge holes are not. Note that many of the components are shared between models. I think some of the rudder parts are shared with the RV-9, and the RV-9 parts aren't final sized. The plans tell you to final-size those parts. So, the RV-14 isn't final-sized everywhere.
Tip #2: A final-sized hole still needs to be checked for burrs. One side of the hole is usually terrific, and the other has a burr. Usually such burrs are very slight, and I sand them off if they are on an interior part (will be primed anyway). If the burr is on the exterior of the skin, I use a deburring tool.
Final-drill is used when all the components have a hole, and they just need to be sized up to the correct size. Match-drill is used when you need to use an existing hole to create a new hole in a component (or two) that doesn't have one.
Tip #3: Be a perfectionist about drill alignment when drilling through thick materials. If you drill from even a slight angle through the rudder horn, you will get oblong holes. Ask me how I know.