PolyDualMesh to preserve zone boundaries and/or baffle surfaces
 

Hi all,
Can anyone tell me how I can use polyDualMesh for models with distinct zones for which I want to preserve the zone surfaces/interfaces? I have tried splitting the mesh into multiple regions and running polyDualMesh on each mesh separately but it remeshes the boundaries differently for each region so I cannot recombine the meshes afterwards.
Any ideas?

Thanks
Ivor