Problem with Weight Sliders

[Restaven]

I’ve been making custom meshes for a new armor set and have had trouble making it work with various character weights. While troubleshooting I’ve noticed that any high/low weight mesh pairs placed outside of the file locations used for vanilla Skyrim are incompatible with weight sliders, even when I put vanilla meshes that should be working in places where they aren’t usually found. 

Replacing the vanilla meshes themselves doesn’t seem to work either, as any changes seem to be overridden by the .bsa files, which is strange. I was led to believe that any loose files should take precedence.

I was wondering if this was just a known problem with SSE, and if you all would recommend using regular Skyrim if thatâs the case. Otherwise, any help would be appreciated.