I believe the reason for a convex boob-armor being a bad thing was explained in-depth in the Tumblr post on the subject (which I thought was linked in the OP but it seems only an image from the post was linked). In short, an impact on the front of the armor would exert so much pressure on the sternum that it would break and the wearer would die a painful death. Even shorter, it's like your armor killing you if you trip and fall. [url=http://martwhim.tumblr.com/post/40061546009/why-do-you-hate-the-shape-of-breasts-in-plate-armor-so]Full post[/url]