there are a couple of chassis intrusion switches on the FW16
i think there was one in the bottom left (looks like a boxy inverted N shape with a black piece sticking up and out from the empty portion of the N, at about a 45 degree angle upwards). There is also one (looks the exact same, but with a different silkscreen label) under the dGPU connector flap. There might be others as well that I havent seen yet.