The timing drops aren't just happening post-shift. The biggest one is well before a shift and again well after a shift. You're too close to the knock threshold IMO.
I'd drop your boost a little and take half a degree of timing out around 5-6000.
Post shift timing drop is fairly common with N54 but I'm mostly familiar with the 6at steptronic. Wouldn't surprise me if it followed the DCT gearbox too.
False knock is also a factor and IAT's that are too hot will pull timing. What octane you running?