I apologize for the small picture. Maybe you can still get a sense of what Piola is trying to show. This is from this weeks Gazzetta edition.
it was right before your eyes near the beginning of the thread.
they are blowing the beam wing with the exhaust. The arms just keep the flow from spreading upward. The arms may also coax the hot gas to take a more horizontal plume shape. They are trying to spread the flow across the wing instead of heaving one focused tube of gas under a little area i think.
We need to investigate the camber on that beam wing, it's possible it's so cambered that without hot gas flow it would stall. The gas flow could permit more extreme beam wing profiles to be used.