@Xstix11 

Thanks for reaching out! I understand that you have a Deco Mesh system with both BE11000 and BE16000 units, and you're wondering which unit should be set up as the main Deco connected to your modem, especially as you expand coverage to your backyard and outdoor office.

For most Deco Mesh models, including advanced ones like the BE11000 and BE16000, all units in the package are functionally identical, so you can choose any unit to be the main Deco. The main Deco is simply the one that connects directly to your modem or router to provide Internet access to the rest of your mesh network.

Key Points:
• You can use either a BE11000 or BE16000 unit as your main Deco. There is no technical requirement to use a specific model as the main unit unless you are using a special Deco model (such as DSL or 4G/5G versions, which have unique ports or capabilities).
• If you want the highest possible performance for your network, you may choose to use the BE16000 as your main Deco, since it is the more advanced model. The rest of your Deco units (BE11000 and BE16000) can be set up as satellites, including those placed outdoors or in your new office.
• To set up a new Deco unit as the main Deco, simply connect it to your modem during setup and follow the instructions in the Deco app.

Exceptions:
• Deco M3W units cannot be used as the main Deco since they lack Ethernet ports.
• For Deco DSL or 4G/5G models, only the unit with the appropriate port or capability can be used as the main Deco.

If you need to change which unit is the main Deco after initial setup, you can do so in the Deco app by following the steps to "Replace Main Deco." Please note that the WAN MAC address will change, so you may need to reboot your modem to restore Internet connectivity.

Let me know if you need step-by-step instructions for switching your main Deco or have further questions about placement and setup!