I don't seem to be able to find anything about the wastegate duty cycles, but I'll keep looking.

P.S.: my tactrix is in Koeln/Germany already, so probably I'll get in by the end of the week.

Ok, I've installed the Versatuner. I don't have the tactrix cable yet (I'll get it on Dec 28) so I'm just exploring the maps. Now (obviously) I have a few questions: 1. how to I raise the idle RPM? Under the "Idle" table I have two entries, "Idle RPM 1" and "Idle RPM 2"...

well, in 6th at 6700rpm you should have about 280Kmph (OBD reported speed which would match the GPS recorded speed you had the 215/45/r18 OEM bridgestones). This should be about 295 - maybe 300 on the speedo

Is it possible (or does it even make sense) to implement LC by controlling the throttle opening rather than cutting the ignition?

I guess that unless they plug a pressure sensor in your intake manifold they can't really tell how much boost your turbo makes, right? So trust your logs, not theirs, let them tell you only how fast and hard the wheels are spinning the rollers. The K04 reaches full boost on a stock engine/intake/ECU...