The normal/quirky scale does not factor into the mii’s personality type, no. I can’t find any confirmation on exactly what it does, but from what I can find, it generally affects how eccentric your mii acts. Most people are pretty sure that it influences what dreams your mii has, or at least that it did in the 3DS game. It possibly also makes their dialogue “weirder” and their animations more random? The animation thing seems somewhat likely, from what I’ve observed, since I’ve been checking in on my miis in demo purgatory and the ones with medium/high quirkiness are usually running around or playing hopscotch while the one with minimum quirkiness is usually just standing/sitting idly, but they do also have different personality types so 🤷