neva thought about it before.
If they are in the correct hatching position yes. The position of the bird is why it zips to the right. If it zips in any other fashion, I would keep a close eye on it because it points to a malposition and can hinder progress.
My zipper stopped zipping. Is still alive. Maybe stuck to inside of shell? She's been like this for five hours!
Zipping should take a few minutes, not hours. A stalled zipper is usually a sign of a problem. Me, personally would finish the process for it, especially if it is zipping abnormally. You might find either a positional problem or a development/deformed issue.