It doesn't matter. When the wheel is up to tension, the spoke threads should be completely covered by the nipple to look pretty, but what really matters is how much of the spoke thread is engaged with nipple thread. Even on 12mm nipples, the thread doesn't start until 2 mm into the nipple. Depending on brand, the thread inside 14mm nipples is only 0 or 1 mm longer. They are only too long if you need to run the nipple thread onto the unthreaded part of the spoke.
It doesn't matter. When the wheel is up to tension, the spoke threads should be completely covered by the nipple to look pretty, but what really matters is how much of the spoke thread is engaged with nipple thread. Even on 12mm nipples, the thread doesn't start until 2 mm into the nipple. Depending on brand, the thread inside 14mm nipples is only 0 or 1 mm longer. They are only too long if you need to run the nipple thread onto the unthreaded part of the spoke.