What to with stacked devices in congested areas will be another topic for another time.
We added two reference planes to our families dimensioned them at 1000mm apart and locked that dimension. We then dimensioned the left-hand plane with a shared parameter called annotation distance, dimensioned it at 1000mm from the origin, we then aligned our Generic symbol for our outlet to the right-hand reference plane and locked it to that plane, and then aligned that plane to the origin plane.
So when we use our family if we have stacked outlets, we can move the generic annotation symbol either right or left, but leave the family in place.
See attached, its a 2016 family