I have a 13m Octane and hate this kite because it has a tendency to "Hindenburg" (When the kite is parked at zenith with little movement for a while it falls forward, overhead out of the sky and loops through its lines).

I adjusted the stopper ball and moved it slightly up on the bar system (when you let the bar go it stops up against this) This seems to have helped the issue some what.

As for the lines, I connect my front lines to the first knot and rear lines to the middle knots or last knots - This helped too but occasionally the kite would back stall so I trimmed my depower and this kept the kite in the air.

This being said, I learnt all the tricks to keeping it in the air and parking at zenith is a no-no!

Octanes are the kite hindenbergs were named after. The common solution is easy as you suggested.
The kites came out with 2 pigtails on the rear bridle. Just rip one off and you're good to go. The good thing about this problem is it means the kites are designed so far forward that it's almost impossible to backstall them.
This means you can load them up with a bit of power for LW and they won't back stall. Even stick those extra PT's on the front lines for a bit more power when the wind is a little light. This kite is not a major performer in any dept IMO, but it does have a better range than most once you get your settings dialed in. I rode this kite in a nasty 10 - 40kt gusty day and though I was teabagging at 10 and dragging my butt at 40 I didn't die and still managed a bit of fun inbetween the extremes. That same day guys on 8's and 10's quit it while myself and a windsurfer on a 4.5m wing were left to it. Fairly tiring sesh but there's no way my current 11 would take that wind. I've tried to set it up for 25+ and it couldn't take it. It's a better kite in it's range but that's one for the Octane in any case. I've tried these settings with tons of other kites and though it can help to a degree, only the Oc really shone in this dept.
The only other kites I've heard of with a similar range are the bandit's and the kahoona's. And I heard that here, not on the water..so try it out for yourself and let us know. Plenty of gusty days left in it yet.
Having gone on about it all like this, I love my 9 and 7m kites now. Definitely the go to have these on hand for the HW stuff.