@bendurso :
so you really need this isMetaParameter when your Parent/master control itself has isPlugInParameter = true...
So in this case the DAW can send some value change to the Parent/Master and it would change BOTH the master/parent and the child/slave
Logic(in particular) gets very upset if it sends a param change command to a control and more than one control changes --- unless this isMetaParameter is set up to pre-tell Logic about this situation...
..well thats my take any way...