It turns out Pernicious especially had been sucking his food; as I started adding less liquid, he started getting less good at eating. I expect a little weight loss or lack of gain around eating, but a week after weaning, he was headed down more. So I discovered his little problem and started prying open his mouth to insert food. He was desperately eager and gained back all his weight that day. He sometimes does a little better on opening his mouth to eat, but the intensity of the experience works against him. I’m back to adding more water and monitoring their consumption a little more. The photo above is him cuddling with Perfecto.
The video below is their eating in action, with full audio. They changed places a lot before I started the camera, and did so again towards the end of the clip.