You willing to share what you've done with your gas line? I'd like to add my free standing 3rd burner the way you have, but up until now I've had to use a 2nd propane tank for it.I have one of these ...did some mod's, installed reinforcement bars (for 10 Gal batches) and mounting brackets. I'm pretty happy with it right now. Still have some items to add, but its ready to go like this.
Edit: NM, I see you still only have 2 burners there. My bad.