What do I need to change inorder to splat 8 to 16 alpha maps

Iv seen it done in other projects and i was told it was possable to have 8 or 16 textures and splatmaps as opposed to 4, but do I chage the matial file code or the plsm2 code on splating? Thanks ahead of time

You have to write new Texure mode in PLSM2 plugin.

Keep in minds that it highly depends on Texture Units availables on video cards. Splatting with a 7 TU cards, you have make a 4 pass material and shader.