Source Files Or Models?

[Mr. Something]

Im thinking about buying this software, is this software able to use source models or files? .mdl .vtx or .vmt

[myclay]

The following file formats are supported;
Mesh Files *.fbx *.abc *.obj *.dae *.ply *.gltf *.glb *.usd *.usda *.usdc *.usdz

If I had to texture source files, I would first try to find the above mentioned file formats if that doesn´t work, I would try to import those Source files into a 3D program like Maya/Blender and then export out as any of the Substance 3D painter supported file formats.
For Blender there apparently exists the following addon: (but i never used it)
https://github.com/REDxEYE/SourceIO