This is an extremely helpful plug-in. It saves a lot of time when compiling a large number of tracks into one flowing audio presentation, be it a live concert or a radio show.
That said, there are two issues which could be improved. The fact that the tracks are not actually aligned but Silence is added to move the audio makes them very difficult to work with after applying the effect. Key commands such as j or shift-j can no longer be used. Instead the beginning of an audio passage is indicated by the end of the previous track, but that makes precise editing rather cumbersome.
Also the labels of the fade and cross fade options should be more specific as to what they do. I know some of them but others not at all and I assume that most Audacity users haven’t got a sound engineering background.
Notwithstanding the above, thanks for this wonderful all-purpose tool.
That’s a limitation of of Nyquist plug-ins. Hopefully that will be improved in the future, but for now it is unavoidable.
Regarding labels, I’ll leave that for Robert 
Thanks very much for the feedback.
You can use the command “Edit–>Clip Boundaries–>Detach at Silences” (Ctrl-Alt + j)to eliminate the artificial silences.
Thus, the mentioned shortcuts (j, Shift-j) can be used again.
I’m afraid, you have to try the different fade types in order to find one that suits you. There’s actually no simple nomenclature available.
Linear is equal to Audacity’s Fade-in/out.
Cosine is that one used by pro fade out.
The double S curve is exactly the same as the old Egyptian pictogram for snake.
It starts with the head, curves down into the neck, goes smoothly into the body, goes down again and ends in the horizontal tail.
It makes the fade in two steps, instead of going down to silence, it stays at -6 dB for the longer part and adds another cosine curve at the end.
This is useful for voiceovers. Let’s say you have an intro music for your podcast and want to overlay the episode number and title, you could use one of those three fade-outs over a long period (e.g. 10 s). It’s like ducking the music during the announcement.
You would concretely do the following:
- Select both tracks
- Apply CIU with a double s fade-out and a gap of -10 s (= overlap).
- Optionally a second time for -12 dB.
- CIU again, but now with “Trim and Chain up” and a shorter overlap (e.g. -9 s)
This moves the voice to the right, where the constant -12 dB level is already established.
You can now mix and render those tracks to fix them and select an additional track to chain up, perhaps with another transition type.
And so on…
I know, some video/audio tutorials would be immensely helpful for this plug-in but I’m not good in such things.