I don't think there'd be a problem with citrus woods, maybe if they were cleaned prior to use, there wouldn't be an issue.
Cork bark is good as well.
I've seen them mounted onto other woods as well, but I'm not sure what kind they are.
No moss whatsoever, imo. Moss is too troublesome to use when growing Chiloschista and stays too wet for them. I wiped out a couple of them just by growing them on moss (and it wasn't even a lot either). One of them was an exceptionally nice one too (
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).
How fast they grow depends on how well they're grown and how well they establish. Some places state some species grow fast. In my limited experience, they don't grow all that fast.
I'm not too sure about this one particular detail, but I believe they produce rudimentary leaves if they're not getting enough light.
Remember, they have a rest period, they either don't grow during this period or grow extremely slow and very little at that.