I have an Aeotec USB stick which I’m making the “master” zwave controller on Hassio. I also have an ISY and Smartthings. If I make the ISY and Smartthings secondary controllers, will that extend my network range?
you’ll probably have to check the specs and see if they support being a “repeater” or not. Usually battery powered devices aren’t and mains powered devices are but as far as another controller, I’m not sure. But you would think so just based on the nature of it being a controller
Z-Wave is a mesh network, so its not like having a WiFi repeater. Having powered zwave devices will typically create a more resilient network and help extend the effective coverage. So if you look at my zwave network below, you will see that the red devices communicate via one or more of the yellow devices.