LFX E39 P0300 random misfire

Hi folks!
I swapped an LFX into my Exocet and have finally gotten around to tuning it. I've tuned my MAF and VVE and everything seems to run very well. However, there are two issues I'm having (with two corresponding threads in this forum) that I'm hoping someone might be able to help me fix. Here's the misfire issue.

Though I can't feel anything wrong (it feels great, actually!), I'm getting a MIL and P0300 code regularly with high load and high RPM. Logs show that it's consistently in cylinders 3 and 6, but mostly in 3. I've swapped coils with adjacent cylinders to no effect. The engine has ~45k mi. I've put in a Monster twin-disc clutch and I've heard that changing the rotating mass can cause misfire detections, but the twin-disc weighs as much as the stock clutch.

Attached is a tune and a log. Does any kind and wise soul out there have any ideas about this issue? Attachment 141581 Attachment 141582