Lots of valid points above.
There is a long thread here
that I have been involved in that has chased down many bits, and it includes a simple test of the function of teh Kompressor and the regulating valve. With these, you can test it without taking it out of the shop, which is convenient.
However, it sounds like your Kompresor is not working, since you have checked the clutch already.
So the big hitter that does not produce a code is the K40 module; it is possible that the unit you had fitted was not a good one, and so has not corrected the faults.
Remove the K40, and check all the soldered joints on the PCB are in good state. Note that even careful inspection may not find all of them, so re-doing the soldered joints is a good technique. (In a way, you have a better issue than Fabio on that thread, since your boost never works, so you have a hard failure. His works when cold, but once hot fails reliably, so he has to debug when hot...
) My car had same as yours; ran ok but would not overtake, and the SC did not engage. Solder on the top left three joints resolved my issue.
Let's start there, and then chase other functions that might contribute to other issues.
Edit: Sensors , when they fail, cause a code, and typically cause a light. If you have not been getting a light, then you do not have a sensor fault, so don't let anyone make you buy another sensor.
This is not in the low power stage of the controller, where the built-in test (BIT) detects a broken actuator, but is in the high power stage beyond the relays, where the BIT does not look. This is relay country, and especially K40.