Benni Boelli (the designer among Armin, Benni Kälin and so forth) confirmed when I asked under a FB post that closed cell makes no difference when flying properly but colapses indeed get more violent/dangerous with closed cell because the canopy can´t take "energy" out of the collapse when deforming. (much like a crumple zone in a car crash maybe as a cliffhanger) So the collapses get more dynamic or canopy can get tangled on closed cell canopy. That is of course not what you want clode to the ground. Also groundhandling becomes a little more difficult.
What they got years of experience ahead now is porbably late stall although running reflex profiles and making the collapses managable and not dangerous close to the ground. This is probably also why diy solutions or other brands copying it would be only advisable (copying is never advisable though
) with large test pilot experiences or very good flying capabilities. So I´m out "just" converting one of my kites which was not designed for flying in the first place.
If it was so easy they would have brought it years ago.
Huge respect to their team.
But man now that you see it works, very tempting to do a licence and get one of those. My local spot is full of cliffs and steep coast lines with soft beach below. (although it´s not legal in Germany being not licensed as a paraglider)