I just got the Alpacaraft Yak with the white water skirt. I did the tight straps like the way that Luc recommend in his post http://thingstolucat.com/pimp-my-packraft/ and I took it to the lake to roll.
The boat rolls fine using the sweep roll and c to c, I am going to post a couple of videos in YouTube, here are
some photos. I practiced self rescue too.