Yeah interesting that they do better in full sun, even though it looks like their ecological adaptation is to be semi-epiphytic. If you place them in full sun, I'm sure you need to pamper them a lot more.
The example of the oil palm got me thinking, "why not?!" I mean how many years until an oil palm starts flowering anyway? Until then you're not producing anything. Plus the old leaf petiole "pockets" provide a place to stick handfuls of fertile soil so you can separate dragon fruit fertilization from the palm fertilization.