Need help optimizing revit files for import

Hi All,
Hoping to spend the weekend rolling up my sleeves and diving into Twinmotion. I exported a revit 2025 file to datasmith, imported it into TM 2025 and am having issues trying to apply materials.
Is it best to have the materials applied, when possible, in Revit before exporting to get them to UV map properly?
I applied a roofing material to my roof and the material changes direction in every roof section. Not sure how to individually select roof sections to manage mapping? And the material is applying to my fascia and Barge rafters as well. How do I separate those from the roof?
Assuming it might be beneficial to apply layers, or materials prior to export. Need some guidance.
Thank You
And in followup- If I go into Revit and make changes and re-export, will I need to reapply all of the previously applied materials?