Much like Flex, saved the popup settings to config files, I'd like to see pop ups for Portal/AGOL be a saved file that auto loads with the service. by doing this you could set the popup settings in ONE file and apply it to every iteration and filtered version of the layer. For example, I have five different filtered versions of Primary UG Lines in my map. The data is customized for different zoom levels, symbology or key data that needs to be highlighted in a separate layer. I have to access each layer and customize the pop up for each, would be much easier to do it once and just reuse that file every time.