That is absolutely true, I do generate multiple copies with different morph set to keep down the file size per model.  It is not necessary to load all morphs if you are only going to use a fraction of what is available.  For example, I have a morph++ loaded V4 model existing in my library, but I also have a separate S4 morph loaded V4 model.  Again, I keep the file size overhead manageable.  This will also keep the scene file size smaller if the models aren't too weighty.  Ideally, if I need to add other morph files, I could individually pick and chose the ones I want, and spend less time loading those.

Word of caution though,  I have seen issues with trying to load all the morph packages into one model.  At best, I've been able to load 3 separate morph packs, but anything else beyond that.  I imagine that all the morph channels become occupied and will not allow any addition set to be loaded in.