can I avoid unity re-importing materials every time I modify a max file?

Sup? I’m with this model which I’m updating quite often. I already gave him materials within unity, and I delete the materials imported from max, because they’re useless! But every time I do some update to the mesh and save, when I go back to unity, a whole set of materials have been added to a materials folder, and that’s if I save 1 time, if I save 20 times, I get that amount multiplied 20 times! that’s a lot of cleaning to do! So I’d like to know if there’s a way to avoid unity importing materials every time I update a mesh!

Select the model and look in the Inspector. Make sure the Materials Generation option is set to Off.