Deacon query

Was an explanation ever provided anywhere as to why the Deacon come out fully formed, instead of first evolving into a chestburster?  The first time we saw this in the film series was Alien3, specifically the Runner, but I didn’t think Scott acknowledged that!?

This makes me further wonder if a deacon could be facehugged!?

Given the mural shows ovomorphs already existed, was this meant to suggest David was not responsible for them?