Leviton releases 5 zwave plus devices--solves low load glow problem

If it’s currently wired as a non-networked three-way, then it isn’t going to work to just replace one device . You have to replace all of the devices in a three-way, not just the master.

So you can use the DZ6HD as a standalone switch, but then there have to be no auxiliaries wired into the circuit.