Manually reset the ID of a map layer inside of manager

Quite often we add/remove layers from our sites as revisions and new data arrive.  Everytime this is done the site loads with a new map layer ID, not necessarily the same as the old one.  This then breaks all workflows set to that previous map layer and the workflow has to be reset.  I can go in and change the site back to it's original ID by opening the site.xml and editing, but it would be great to be able to set the layer ID directly from manager.