Hi Oat,
I think you collection is more impressive with H/L and L/L nep species...
Mine just some regular L/L neps...
Anyway, I used 70% burnt clay : 20 % perlite : 10% coco chips for N. madagascariensis. As far as I observe, I found this nep took a while to acclimitise to my new growing condition. Once it's settled down, it'll start growing with 1-2 new pitcher per month. My plant is still fairly young, still need to observe more.