It looks like the plant spends quite a bit of energy to make a pitcher...probably about the same as 1 large leaf.
This is probably unconventional thinking at the least and sacrilege at the most but:
With a smaller nepenthes I will prune them down to 1 before they develop fully and allow 1 new one once the old one dies.
That way the plant is spending it's energy for overall growth and leaf production. Once the plant get's larger ill allow 2, then 3 and so on.
Once the plant gets 12 inches tall I think will leave it to it's own devices.