Ultimately, what I am trying to do is to make a plugin that replaces all instances of an event dispatcher node in my project with a custom event dispatcher during a pre-build step.
At my current level and ability, this is effectively black magic, but having done some poking around in the BlueprintGraph and Blutility section of the API, I believe it is at least possible. Unfortunately the documentation for these sections of the API is essentially nonexistent.
If anyone knows how to at least parse through uassets to get instances of a given node, I would be very grateful.