Nif exporter being a pain

I made a few changes to the Blood Dragon Armor's skin weights to address issues I had with the initial weighting. Now, the upperarms don't raise several polygons on the breasts and the stomach plate isn't awkwardly deforming. But there's a hitch: The _0 model is losing vertices upon export. These same changes, when applied to the _1 model don't change the vertices on export.

So, what's going on? Initially, I thought it was because I moved the belt away from the main body to reduce selection scope. Not doing that, however, did not prevent the vertex disappearance. Next, I thought the breastplate was to blame. Once I shifted the weights around and exported, the vertices disappeared upon export.

The vertex count did not change in 3ds Max and, considering the vertex count changes upon export into .nif for whatever proprietary reason, I assumed the exporter was to blame. Now, the _1 did not lose vertices, which led me to believe the issue was spacing. The _1 model's vertices are too spread out to be hit by the welding.

_0 model: 10740 vertices

_1 model: 10740 vertices

 To test this, I tried changing the weld parameter's precision when exporting the _1 mesh. Values ranged from blank spaces to 0 to 0.0 all the way to 0.000000. No change. When applied to the _0 mesh, though, every single value had no effect on the lost vertices.

Both exported. _0 missing 2 vertices

The only solution I can think of to prevent this is to weld the vertices of every element. This would require making the _1 model for a third time. Why? The welding would change both the vertex count and vertex numbering with no guarantee the same exact operations will produce the same count and numbering on the _1 model. I think.

Edit:

Welded every single vertex within .01 units on both models. Still getting the 2 missing vertices.

Edit:

After deleting elements until the discrepancy stopped, I've found the pauldrons are where the vertices go missing. Now I get to either a) leave them slightly messed up or b) separate them into a third component of the armor and fix their weights.