Yes, the target boost pressure is indeed the figure you are after.

But, do it gradually. Try and make it control 0.8 kg/cm first, by setting 0.8 kg/cm and a duty of 30%. Adjust only the duty value until you are making a fairly reliable 0.8 kg/cm. I know that this is only slightly higher than actuator presusre. Don't worry if it drops off a little.

Then raise the target to 1.0 kg/cm and the duty by 10 and see where that leaves you. Each time make sure you hit the target boost. I know it's a pain, but it is the best way if you are struggling as there may be another reason and this will pin-point where the problem is occurring.

Once you have hit 1.0 kg/cm, go for 1.2, as above. Raising the target to that and duty by 10 and trimming to hit the target.

Once the controller has reached your desired boost level, then you can begin the learning process. I can tell you how to do that too, but lets get over one hurdle at a time.

Are you sure it is piped correctly?