(the belt or strap locate at the middle side of the breastplate or the plackart)
Won't the belt become easy target to be cut or to be worn out? Making the armor prone to break up or unable to cover properly because it's getting loose during battle?
examples (click to enlarge):
image from pinterest
image from https://steel-mastery.com/milan-style-full-plate-armour-1450-1485-years.html