Is there any best practise for handling materials when importing V5 Data to the platform?

If a 3DX user is taking data from a supplier using V5, is there any recommendation on how to handle materials? When importing the V5 data, the mapping tables can be used but it is not clear to me how materials are respected in this workflow. Is there any advice on how to avoid duplication of materials when doing the import and how the mapping tables recognize previous imports of materials.
@RH @MA