Integrated Protection provides the Warforged +1 for their armor class. It also provides Distinctive rules with regards to DnD armor. According to Eberron: Growing from the Last War, Warforged can only don armor they’re proficient in, and they need to spend an hour incorporating any armor that isn’t a DnD https://gnome-wizards57045.wizzardsblog.com/28164210/how-much-you-need-to-expect-you-ll-pay-for-a-good-goblin-best-class