Editing individual Layer properties for huge map services

I am putting together several maps that use a single map service that is comprised of hundreds of layers/group layers.  I have set up a parent/child relationship where all of the maps (children) reference a large map (parent) so that we can do most of our data edits at the parent level.  This has been fairly useful so far.

However, many of the layers from the parent site are hidden in the different child sites, depending on the audience for the child maps.  I noticed that on the child sites, these hidden layers can still show up in identify operations on the map.  I know how to turn off the identify in the layer properties at the child level, but this method is incredibly time-consuming, going through each individual layer and turning off the identify option.  Wondering if there is a way to batch-edit these settings for specified layers.

Normally I would do this in the site xml file, but because we are using references (parent/child relationships) the xml files for the child sites do not always contain the layers in question.  This is a long-shot, and a unique scenario, but I am curious about this.  Have heard rumours that Essentials 4.2 may have more options for batch-editing of layer properties.