I fly it on 4 lines, not one problem. When really light I use the fifth line bar. I ride it on a 4 line low Y when I want a bit more turning speed. 4 line high Y in its upper wind range and the five line when really low winds to give me that fifth line relaunch ability.
Works just fine on a 4 line, but of course make sure you use the 4 line point on the front lines to connect.
Got an electric pump, or that leading edge will literally kill you to pump up...lol!!!
Actually I prefer it on the 4 lines lower Y all up, opens it up a bit.
Valves aren't an issue but the bladder material (and leading edge) are thinner than normal for weight, so you could have some bladder patching to do now and then...
Just love how this kite flies, stability with efficiency, a really excellent combination.
But it couldn't and can't compete with the other race kites, (aka the edge) hence I can see why it was changed. Bummer dude...