Long-form free improvisations tend to…wander, losing their direction like a lost soul blowing with the wind, this way and that. But this improv is focussed. Or at least I say it is.
It works for the same reason as the shorter one. And it’s simple. It states a theme and develops it incessantly. Too incessantly? Maybe so, but you can follow the thread. It makes musical-logical (though perhaps not musicological) sense.
But a long-form free improvisation has a burden that shorter improvisations don’t: you must not only develop your stated themes but do so with enough variety to keep it from devolving into a kind of Wagnerian miasma. In that sense, they are not unlike extended composition; you must keep the narrative moving. You need an exposition, development, and some kind of closure.
Does this one past muster? Again, I say it does.