Car turned out VERY nice man!. I love it!. I'm having misfiring issues as well at full boost at the end of 2nd gear when switching into 3rd occasionally and that's with colder plugs. My ignition coils have also been replaced. At this point it's got to be injectors or fuel pump in my opinion. So might want to keep those two things in mind. But since your kit was designed with the current injectors and fuel pump your issue may be just the spark plugs. Try out the Denso IK22's like I recommended, there cheap and worth trying just to see if that fixes your issue.
2000 BMW 3-series supercharged stage 2.5
2004 Maserati M128 GT
2006 BMW M3 - SOLD