For the DAZ figures this is already done, there are channels in all their figures just for this purpose.  You can distribute morphs simply as pose files, see pretty much any original morph for examples (a couple in my freebies e.g.). 

For the EF figures, blank dials are not included in the CR2, so you can do this just fine the way you've already discovered with PMD files.  Who told you this method is no good?  What's wrong with it?

edit: to clarify, the DAZ figures are done completely differently from the EF figures, and the DAZ method of "INJecting" morph data does not apply to the EF figures.

My Freebies