Recently we've been migrating our manual printing workflows to custom printing services at our ArcGIS Server instance. Everything was fun and games until we stumbled upon some Layouts with more than one Map Frame pointing to different Maps.
Most of those layouts with more than one Map Frame look like this one below:
Basically, they are composed of one main Map Frame focusing on the Area of Interest and one overview Map Frame which is a zoomed-out version of the main map.
After some googling I find out that the ExportWebMap specification doesn't cover Layouts with multiple Map Frames, forcing us to name the main one as WEBMAP_MAP_FRAME and leave the other Map Frames blank. Have any of you faced a similar problem? If so, how you solved it? We are currently considering writing a more robust Printing Service that will generate its own Web_Map_as_JSON parameters internally resulting in multiple PNGs for each Map Frame and later on binding it all together in a final PDF down the pipeline but... it seems VERY janky!
TL;DR: Is it possible to create a custom printing service for ArcGIS Server to print a Layout with more than one Map Frame pointing to different Map Services?
Oh! I almost forgot! I am using ArcGIS Pro 2.7.3 and our Enterprise instances are running 10.7.1 and 10.8.1.
Any help will be appreciated!