Using DZ6HD-1BZ (no aux) or Homeseer WD200 in a 3-way?

You can change the association groups for any mains powered Z wave device by just temporarily assigning it to the Z wave tweaker DTH. All the tweaker does is expose the Association group and parameter settings for the device and let you change them. After you have everything set the way you want to, you just change the device back to your every day DTH and the settings will be retained.

All of that said, why don’t you just use the “mirror” Option of the official smart lighting feature in the smartthings classic app? It’s a lot easier to set up and it’s automatically bi-directional.

Or were you looking for something that would work even if your smartthings hub was not functioning? That’s really the only reason to use Z wave direct association if you have a smartthings hub.