Piggybacking on to this... I've currently split my home network into multiple VLAN, so that the IOT stuff can't access the "trusted" devices (or internet, depending on device).
However I realized it would be interesting to MITM the traffic and emulate the services these devices try to connect to, to see what data they are leaking. Does anyone know if there are any readymade software packages, or even tutorials, for this?