I did some messing around with the NDS2 config and channel files and things seem to be working as expected... for now. SENSOR channel data can be acquired for all sensors on all hanging optics.
What I did:
In any case, as I said, everything appears to be working now, but as soon as we try to generate a new channel file using the prescribed means, there will inevitably be channels omitted. Someone who knows more than me should get to the bottom of this and wiki a strict, detailed procedure for how this is to be done.