Need help solving mesh distortion when exporting to .nif

[CarbonWaffle]

I'm getting horrible vertex\face distortion on some (or all) of the meshes i export from Max to .nif. I already exported in the past, but i didnt notice anything wrong until now. Usually i'm running 2018 Max with this plugin and it works fine for Fallout 3/NV. Some examples:

This is what i have in Max viewport:

and this is after export in Nifscope:

Another example with a simple sphere in Max:

and after export in Nifscope:

I was blaming the plugin and tried to use Outfit Studio, but it gave exact same result. Then i switched to Max 2013 with BGS official plugin, same result. Reset XForm helps mitigate the issue, but it still gets distorted. I tried changing Units SetUp, export, import in fbx or obj and back. If i import a vanilla .nif file into Max, it looks fine even after i export it back into .nif. Only happens with imported .fbx and .obj meshes which look completely fine in Max, Blender, Outfit Studio.

Also looks correctly if i export into F3 or Skyrim(SE) .nif format.

[CarbonWaffle]

I took a look at some of my exported meshes and most of them were fine. But some meshes like this helmet here got distorted a little. The distortion seems to affect only small scaled geometry where vertexes are clustered together.

After doing some tinkering i found out that object pivot point affected the exported .nif result. I tried putting pivot point of a helmet model from the center of the scene to somewhere far away and after the export, the helmet became extremely distorted.

So here is what helped me:

0. Save\Export the Skin Modifier of your mesh.
1. Remove Skin Modifier, select your mesh, Command Panel --> Hierarchy --> check "Affect Pivot Only" --> Center to Object --> uncheck "Affect Pivot Only".
2. Utilities --> Reset XForm -- Reset Selected.
3. Utilities --> Collapse --> check "Modifier Stack Result" --> Collapse Selected.
4. Restore Skin Modifier.
5. Create --> Helpers --> Dummy, place it at zero, link your mesh to Dummy (This step is only needed if using BGS official plugin and you dont want your mesh to be put in the center of the scene).
6. Export.

[South8028]

There is an oddity in bgs nif exporter. If the Pivot point of the mesh is far from the actual mesh, distortions occur during export. For meshes of the body, face, hands, it is appropriate to use 0,0,0... For further work in os. But... The more polygons and the further the mesh is from 0,0,0, the more deformations. You should also know... The actual coordinates 0,0,0 os and 0,0,0 3ds are not the same. There is a microscopic displacement.