Is it possible to switch of zigbee for 8 hours by plugging off the zigbee stick or by deactivating ZHA? Or will devices get lost?
(I want to test other zigbee hardware and I don’t want to mix the mesh)
Yes, you can unplug the stick without losing devices.
Will devices shut down if they cannot reach the coordinator? Or would it be possible to unplug the stick for weeks?
They keep searching for the coordinator
They will not shutdown, but they will go into a type of “hunt” mode like @francisp mentioned. This isn’t a bad thing necessarily, but extended downtime will drain battery devices a little quicker.
Would it not depend on what is meant by testing other hardware? Whare you wanting to test?
FYI, you can not connect a Zigbee device to a other Zigbee gateway, so will not mix networks. Just put new Zigbee gateways on a different Zigbee channel so that way they will not interfere with each other.