Holy monkey yeah. The banjo burners have really high btus. I know with my burner it is 180K btus. That is why I would never use it in contact with anything but concrete or pavement (mine sounds like a jet engine

). If we use our burner to direct fire something for a 5-10 minutes the legs for the burner get hotter than a $2 pistol. That was why we really started to push into the eherms concept lately to maintain the mash temps vs. our original plan to direct fire the MT if needed during a mash.
You still get the heat with an eherms but it is less apparent because the heat is all going into the wort and not glancing off the pot and acting like a space heater. If you aren't concerned about steam you have a lot of options with even standard box fans strategically placed to induce airflow in the summer. Cheaper than those vortex fans and... will certainly work.