Inventory existing controllers first
List Apple Home hubs, Google hubs, Echo devices, SmartThings hubs, Home Assistant, and older Aqara hubs. Note which devices are Matter controllers and which are Thread border routers.
Choose the primary commissioning ecosystem
Add the M3 and first devices in the ecosystem that will own day-to-day setup. Share them to secondary Matter ecosystems only after basic control and automations work.
Choose Ethernet, PoE, or Wi-Fi deliberately
A wired path can reduce one variable during setup. If using PoE, confirm the switch or injector and cable route; otherwise plan USB-C power and network placement together.
Migrate in small groups
Move one sensor or automation at a time, verify household access and notifications, and keep the old hub available until the important routines have survived several normal days.