Wow I am sorry to hear that, I also have 2012 KW T660. We have only been dealing with SCR system not doing a complete burnout, after about 20-30k miles we had to find a cummins place to replace the injectors for the DEF and reset the ECU.... I am still waiting to see what Pape kenworth in lathrop ca did but they ended up fixing the problem. only had to pay for rush shipping and hotels for most of the problems. So far the only real big ticket item we had to pay for is a tow after my brother ran through 2 deer over near joplin mo last year within the trucks first 1200miles. The only reason we had to pay for the tow was because it was a week after the tornado went through and the KW shop got hit and the nearest shop was in Springfield.
Hopefully your bugs will get worked out sooner than later.
Mine is on its way back to KW again. Found out the other day that it has a recall issue, something to do with a break valve. Well in there, going to have them run another DYNO again. Starting to pull like crap again with very little power. Was told that after over a certain bunch of miles the truck would start to run better, and seems to be running worse. Going to get them this time to get the HP back up to where it is spec'd at, 500.