Ok, that makes a bit more sense. 
Now when you refer to "native Z-Wave", are you referring to the long obsolete OpenZWave-based integration (legacy Z-Wave), or the Z-Wave JS official add-on? If you are referring to the latter, you can follow this guide to switch:
If you mean OpenZWave, there's no migration path. You can just install Z-Wave JS UI and start over. You don't need MQTT.