Hi TS,
Heat from direct sunlight will encourage the Cephs to produce offshoots. That is why your pitchers are not getting larger. Interestingly, when Cephs are grown in air-con room, they do the reverse. Less offshoots but larger pitchers.
This pot of plant was grown under lights at my balcony. Until about a month ago when I discovered that it had mealybugs, I moved it to an area with natural light. It is doing even better with more air-circulation. I also try my best to keep the pot cool by hiding it behind other plants.
Cephalotus can be grown in live sphagnum. I used to have a large pot of it for about 2 years. I also have a few small plants growing in it inside the N. ampullaria pot. They started out as leaf cuttings so I just decided to leave them there since they are doing well.
Yup, D. prolifera flower stalk. I can't be sure if it will work because after I got it from a friend, I read online that the new plants will develop on the flower stalk while it is on the plant. LOL Well, So far so good. The rhizomes are sprouting and the flower stalk has grown quite a bit. Sphagnum moss is amazing for cuttings.