Ok, now I got it to work. If I drag the suit now on genesis, it conforms without a problem

But there is still a bug. If I load the suit first, then load genesis, then conform the cloth to genesis, it blows up again.

So it looks like the conversion causes some kind of conforming bug and that's why it fails with the DSON loader. (the script does not conform the item)

Try it out for yourself (load suit, load genesis, then conform)