The later waves (basically everything except Marvel and a few models from waves 6, 7 and 9 ) are available as part of the Heroscape mod for Tabletop simulator, the meshes and textures (.obj and .png/.jpg) should be compatible with HexScape but I believe HexScape requires .mtl files for each model (which Tabletop simulator doesn't use).
I think it's possible for you to make these missing .mtl files without using Blender, by making copies of one of the existing .mtl files and editing it in notepad to change the texture name and model name (which you get from the third line of the .obj which can also be opened in notepad).
If you don't own Tabletop simulator you can still get the models and textures it uses because they are all stored in the cloud so you just need the corresponding URLs. I have a badly organised text file where I keep a list of all the links. You can get it from
here. Just search for the name of the model you want, the entries are (for the most part) in the format:
Name
Diffuse Mesh (pastebin)
Diffuse Texture (imgur)
Low polygon non-convex collision mesh (pastebin)
Army card advanced side (imgur and imgland)