That is a beautiful plant! You've done a great job.
The reality is Nepenthes are more vine than bush. Mine, from Home Depot and about 4 years old, is 7 ft tall - its actually taller but, the greenhouse roof is 7 ft so now its traveling sideways. The stems between pitchers and leaves will twine around anything they get near so, maybe a trellis?
I have never heard of anyone pruning a Nepenthes so, I'm not sure how the plant would react.
, any thoughts?