This is truly amazing. 43 seconds.
I trained myself in tail draggers, three different Citabrias. Did all the short-field and soft-field drills, but never anything remotely close to this.
I’ve done similar in hang gliders—but their stall speed is on the order of 13 mph.
Do note very closely on the landing, the rudder action. What he’s doing is flying basically in a total mush. Half of his wings are stalled or very “dirty” and inefficient due extreme angle of attack. But tail draggers have huge rudder authority by design, allowing to fly deep into stall space and use the rudder to keep it from developing into a spin on either side, like balancing on the head of a pin.
A spin at that low altitude means you’re going to crash. No possible way to recover.
We used to practice this very thing in the Citabria, but at altitude, where accidental spin entry is easily recovered.