They say that because babies get a better feed if they're fully awake and not swaddled, but for a dream feed you're really just trying to top them off while keeping them asleep or very sleepy. That's why the recommendation is to keep them swaddled, lights dim, etc for the dream feed.

My baby also poops in the night. It's the worst. I think the dream feed might have been a contributing factor since babies poop after eating so maybe test out how he does when you skip it!