A pattern we use in about:debugging is to only keep the actor ID around in our data model. And when we need to perform a request, we retrieve the front and call the method we want on it. We did this both to keep our data model very simple and easily serializable, and also because some of our debug targets did not have fronts. After Bug 1510654, all our targets should have usable fronts. We could keep the fronts in our data model and directly call methods on the front instances instead of having to first do a lookup by id.