It is possible to send the audio output of one chain to another chain. However, in the selection it isn’t clear what you can choose. In the image below I have three chains which can function as audio out for the selected chain. All of them are called ‘Audio Input 1,2’.
I think we could do better, e.g. using the chain numbers to name these inputs (“Chain 3”, “Chain 4”, etc.). Maybe adding instrument/preset if space allows.
First—I had but one audio chain—I thought this was the ‘general’ audio input, like, mixed in with the audio inputs of the sound card. Utter confusion arose. But maybe it’s just how my mind works.