For this, I will call it “workaround”, two Z-Wave SmartHome gateways are needed, which communicate with each other via https or MQTT. Physically, these are two separate Z-Wave networks.
A possible and relatively cheap solution for the second Z-Wave network could be a Raspberry Pi 4 with a Z-Wave USB stick and HomeAssistant as operating system.
the idea triggered my interest and made me think of the early years of (IP) networking. At that time legacy protocols were encapsulated in an ethernet frame for transport and at the end unwrapped again. I did a very quick and dirty google search and found something on Z/IP gateways. I’m not convinced it’s an answer on your question, and it seems in an early stage of development (so still a lot of DIY). But I’m hopeful a solution may exist (soon). It would certainly open some new possibilities.
A starting point: Smells Like...Convergence!
Or google on Z/IP gateway
Don’t shoot the messenger, I only had 2 mins to spare
With this method the Virtual Motion Sensor on Homey Two is always in sync with the real sensor on Homey One.
I’ve used this method to move all my Zigbee devices from my ‘production’ Homey to my Development Homey so I could do a Zigbee reset (after the Zigbee rewrite) without interrupting operation. I’ve done extensive testing and found the method of keeping some Zigbee sensors on another Homey and using http communication between the two Homey’s is at least as fast and sometimes faster than moving all my devices to my production Homey.
While I did this with Zigbee devices this method can be used with any and every device your Homey(s) can support.
Why did I use http requests with web hooks and not MQTT? It is built-in functionality, no apps needed thus no extra CPU and memory usage. (And it was supposed to be temporary )