Thank you for your answers. I’m trying to use export/import to FBX, but it messes my material slots.
I tested two methods: 1) export/import, 2) export, modify original’s mesh source file, re-import.
Both methods break existing material slots (remove assignment to triangles) and add new ones (named like materials). Last LOD (billboard) looses its material slot and doesn’t get replaced with anything.
I’m trying to work out a better way or write code to make that process faster and correct. But it’s not fast at all. 3-5 min per mesh to re-scale is a lot of time when you work with hundreds of meshes.