The no-longer-a-mystery plant — now officially known as Nepenthes truncata x (spectabilis x northiana) — is now in a 200mm pot.
Three pitchers are now open. The first and second are the largest and have to be supported or their weight will put too much stress on the plant, which may explain the high mortality rate its gifter warned me about.
The stakes are about 115cm; the central one is for the vine and the other three form the frame on which the pitcher-bearing leaves are supported.
The following arrangement allows the pot to be put in a watering tray 3 to 5 cm deep:
The base of the pot contains a layer of geotextile fabric to prevent the media from washing out via the large drainage holes. On top of that goes a layer of scoria to provide good drainage and weight, and then the pot is filled with a mixture of coco-chip and coco-peat. This media is soaked and rinsed many times to remove salt before it can be used or it will kill the plant.
The root ball of the plant is kept above the halfway-mark of the pot to prevent waterlogging of the roots, which is detrimental to plant health.