I believe a simple but powerful tool would be the ability to bundle sources together or have a source that is broken down further. For example, if we have multiple different high school events, it would be useful to be able to see both the specific high school turnouts, as well as the turnout of all high school visits.
This could look as simple as creating a primary source, High School Visits (2019), and then allowing sub-sources that fit into the primary source or can be bundled into one source. It would help us strategize as we would have better information on the performance of a group of related sources in a convenient way.