My Model in blender has around 4k Verts. When i import to Unity, there are 12k. Actually none of the Informations provided by Unity are even close to the stuff blender tells me and its clearly fasle. There is also no change in Unity doesnt matter what i do.
This sound understandable but how can it be that i remove 4k Vertices and nothing changes? The Model has lower Quality you can see it clearly but the Vertices stay there. The model had 8k and i removed 4k but it stayed at 12k.
You have the model and the setup, you can do your own investigation!
Get something like ExportOBJ or the Unity FBX exporter, select and export the model from Unity, pull it into Blender and study the differences in the geometry between the original and the one cycled through.