How were your launches? Wheel spin, DCT off, etc.? It seems like a little better launch is definitely obtainable with your current mods and tire setup. I've seen 60ft times in the 1.8 range with stock run flats so if you can manage that kind of 60ft time it should translate to a 12.6/12.7.
With the the N55 motor for bigger gains you might be better off with a jb4 and intercooler. Also depending on how you feel about circumventing smog stuff catless downpipes also provide large gains. I have the Dinan stage 3 on my car with intercooler/oil cooler and while it is definitely quicker than the stage 2, the difference is more apparent on a track than in a straight line. My best time on a vbox was 12.52 with a 1.79 60ft time, so it doesn't seem much different from yours. Once I'm out of warranty I may switch as well, but right now the car is way faster than the suspension and the brakes can handle and I track the car more than I drag race it.
There are a bunch of guys here and on n54 tech that can point you in the right direction with the jb4 if you decide to go that way.