Right but the whole point of multiadmin in matter, is that you can share devices to other ecosystems. Eg - you can add a device to Google Home, and then share it to Alexa, Apple, SmartThings etc - but in these cases, all these ecosystems have their own radio, so that is the part I don’t understand. It doesn’t make sense that a device talking to 5 (that’s the matter maximum) different ecosystems would be physically talking to 5 different networks too. Each ecosystem has something called a fabric, which essentially handles security and authorisation - by installing certificates on to the matter device.
But ideally we could do with some confirmation of this.