"... which I imagine could suffer if not properly suspended with telekinesis or similar buoyancy."
"It's also worth remembering that the human brain consumes a vastly disproportionate number of calories for its size, and were that true for contemplatives, they might have to eat a staggering number of calories to sustain themselves. With an atrophied body, that means very little stomach space to digest food and a limited intestinal tract with which to absorb nutrients. In order to meet their caloric needs, they would favor nutrient rich foods interspersed with calorie-rich supplements. That might mean your average contemplative drinks meat-shakes, pops vitamin pills, and instinctively salivates over candy bars"
Given these two quotes might it be that they do the whole "brain in a jar" thing for sleeping/eating? Combine those two annoying physical activities together, let the ID take care of these "lesser" functions by sleeping in a jar full of a nutrient dense "bath"?