I've imported csgo player, and both armature and mesh works great in blender, like it has it's bones assigned, weight maps and everything, but on smd export it just joins all mesh together to 0 bone. At the same time it does export weight maps with actual bone IDs for triangles.
Here is folder with original smd, blend file after import, and exported smd: Google Drive[drive.google.com]
Blender 2.83.2 & BleST 3.1.0