Hi Pop,
Well, I used my 'normal' mix; 4 parts coco cubes/ 1.5 parts pummice (various sizes)/1 part charcoal and sometimes a handful or two of chopped sphagnum. I don't have any special insight into the mix for these guys but after seeing the comment about 'light' watering I'm wondering. I just went down to check and all 3 plants have miserable looking pitchers right now...of course I've been gone for almost 1 month too! But I'll probably switch the mix in at least two of them to a better draining mix.
After seeing the burbidgeae in situ, I'm wondering about the role of the ultramafic soils. The rajah, villosa, and ,I think, the burbidgeae all seemed to inhabit zones where this was the predominant soil type...I wonder how much ultramafic soil is available in Japan? Maybe we could set up a trading Empire!
I'll PM you some other thoughts soon.
~Shawn