OK - I put this together much faster than I had anticipated. It plays pretty quickly and I glaze over a few operations that should probably have a bit more detail. Let me know in the comments for the video if you would like me to break this down further.
This tutorial demonstrates how the mocha 5 plugin for media composer can be used to roto and track and object with the output then fed into Sapphire's Effect Builder as the mask channel, all from the Media Composer timeline