@Ptsuisse Hi, welcome to the community.

Here are some details for your reference:

Ethernet Backhaul already has a higher priority than WiFi Backhaul in Deco Mesh. And if the LAN connection drops, the satellite Deco could switch from Ethernet Backhaul to WiFi Backhaul.

I hope you can further elaborate on the request of "Pouvoir lors de l'installation nommer manuellement les zones où pouvoir le refaire par la suite". The Google translation version doesn't seem to make sense. It would also be very helpful if you could provide some screenshots.

Currently, Deco doesn't allow multiple IP ranges for the Guest Network. If you want separate SSID settings for 2.4GHz and 5GHz, enabling the IoT network with another SSID would be a good option.

Thank you very much.

Best regards.