How to update (reimport) FBX mesh only, not its materials

Let’s say I have FBX model that I have imported to UE4 where I reassigned its original materials to my predefined ones inside the project.

Now let’s say I slightly updated my FBX design and I would like to update it in UE4 but I want it to retain the materials I assigned to it inside UE4 so that I would not need to go over the reassigning process of all of its original materials once again.

So is it possible to do it the way that only the FBX mesh(es) would be updated without (excluding) its original materials and images (some materials have images)? I mean I know I can uncheck all the original materials in import properties, BUT that would make the model material-less as my new materials are not at the same level as the model itself (they are in different folder inside the project Content folder).

Facing the same issue here.
@anonymous_user_ec808062 did you found a solution?