Oh dear, I'm using Poser 7 and like all my software I guess it's outdated already! (I have an old Mac)

I certainly don't mind leaving my textures as mc6 files, in fact that's great! Saves a lot of trouble. It is slightly annoying for me though since I'm using an older version of poser and  can't access mc6 files without going into the material room. Most of the textures I've purchased are MAT poses which is why I wanted to make mine like that too.