Pictures to come soon. My Catts are productively producing leads already. But I am unsure as to how to detect whether or not sheathing will come soon.
Overall, they reside next to the window facing North Easterly. They get fed once a month. And they get watered once a week. I drench them whenever I water. So far it's been a good and productive 6 months of orchidship, if you will.
If there's going to be a sheath on the new pseudo-bulb, it will form at the same time as the pseudo-bulb itself. The sheath is shorter than the leaf so the pseudo-bulb and the leaf need to be almost fully grown before you can tell if there's a sheath. There's no way to know a head of time, if a sheath will form or not. But the other part of the story is that a sheath doesn't mean anything. Some pseudo-bulbs with sheaths will form buds and some will not. Also pseudobulbs with no sheath can still bloom.