How to prevent certain Zigbee lights from being used as routers in a stable deCONZ network?

[flowbert]

I believe that it is not possible unless you find a way to modify the device’s firmware.

DeCONZ Conbee II - Device Management (Define Lights as Endpoint, Individual Still-Alive Checks)

Hello, not good, a device need to be powered all the time, the network is dynamic but do not abuse. It’s not a setting, a device is an endpoint or a router, natively. That happen in the API have nothing to see with that happen in the zigbee network. The unreachable state of a device in the API is just an information guessed/estimated by deconz according to network reaction.