Why would someone use a report map with an overlay as opposed to a report map with a join? What difference does the 2 give when it comes to selecting X out of Y fields for visualizing in a sample report?
I'm not 100% sure what you mean here, but one good use for an overlay is if you wanted to have the legend inset into the map rather than a seperate object to the side.
Can you explain what you mean a bit more/give an example?
