For people familiar with jump maps in the realm of TF2, you understand the wide variety of creativity involved in making the maps.
Much like the Pyro plug-in, where he is able to gain speed/height with the airblast, I request one similar with the Heavy.
Upon firing the minigun, the heavy gains a linearly increasing speed boost the opposite direction of the bullets. The skill required to heavy jump would still be considerable because he cannot strafe while firing and cannot see where he is going (since he is being pushed in the backwards direction). This would attract newer jumpers who cannot do the harder jump maps and have fun with a flying heavy. This could be seen with the pyro where the plugin was available in the server.
The details on the modification are still yet to be decided (max velocity, acceleration, changes in momentum from firing in different directions, etc.)