I guess this is as much a Magic Lantern as a general Canon question.

AGC in Magic Lantern is documented as "applied in digital domain". Is it correct to say that if the output of the pre-amp is clipped, AGC won't do anything for you?

The "Sound Recording->Auto" in Canon's Menu: is that adjusting the gain of the pre-amp automatically, i.e. working in the analog domain? If so, is there an equivalent "auto" in the Magic Lantern menu?

This is where I'm coming from with these questions: I'm only interested in my camera's audio for dual-system sync, and as a fallback in case something goes wrong with the separately recorded audio. I won't be in a position to actively monitor or adjust the camera's audio gain.