Without cryptographic pairing (and a hard requirement at that) and secure channels that aren't optional, none of the setups can really be secure. SDCP tried to

Without cryptographic pairing (and a hard requirement at that) and secure channels that aren't optional, none of the setups can really be secure. SDCP tried to do this, but with so much being optional and scoped smaller than the actual attack surface (pun intended), it's about as good as TPM-over-LPC. As soon as it's optional or can be exchanged/replaced with no side-effects, you're screwed.