FWIW I tried following the instructions with a normal branded dash, and it is clear that the IoT button has a different firmware.

Differences: * Amazon ConfigureMe network uses WPA2 for the IoT button. No encryption for the branded button. * IoT button has extra fields (according to the documentation) that the branded does not. They are for a certificate, private key, REST endpoint, region, and a checkbox to agree to TOC.