Oh, I’m not sure running a second controller helps that much in that case.
Are you planning on using Wifi mesh or an extender? What I was saying would be good if you have, say, a separate building that has wifi but is too far for z-wave. I use mine for a few outdoor long-range z-wave devices where the controller is away from my main house controller.
Seems like z-wave mesh is your best option on a single controller.
I’m running HAOS which is why I went the extra add-on approach. If you are running HA in a VM I’d probably run a separate container.