Modifying MP to support multiple video streams simultaneously

I’m looking for a way to modify MP so that it has the option to view multiple video streams at once using gstreamer.

I looked through the source code and wasn’t able to determine how the videosink is currently set up. In Gstreamer.cs there are many useful methods but I couldn’t find how they are currently being called and implemented on the FlightData display.

What would be the best way to go about implementing a multistreaming functionality? Should I modify the source code, or implement a plugin?