I have just bought a couple of Miele devices, an oven and a fridge, which I want to expose to OH2. After reading the documentation, I thought I would have to buy a Miele@Home XGW3000 gateway to do this.
However, it transpires that the Communication Module XKM3000Z, that the oven needs, is also a gateway and is recognised as a thing by OH2. If you create a new system under system settings on the oven, it creates a second thing, which is the oven.
So, the XGW3000 appears to be not only relatively expensive, but also unnecessary.
I believe that I can add my fridge to the system controlled by the oven too, though I haven’t managed to do that yet.