No, you can't do it like the old days with a boost controller because the ECU will see the increased boost and retard timing and fuel delivery to try and lower the boost. That is why you have to 'trick' the ECU.
Again, in the old days, the ECU would cut out at very high boost levels. This is counteracted by installing a second valve similar to the wastegate valve to fool the ECU and extend the boost cutout.
Can't do that now since (i beleive) that the boost sensor is electropneumatic and is located in the intake manifold (there are two sensors that I can see). If someone with ECU knowledge can tell us what that signal is (4-20mA for example), we can provide some circuitry to keep the wastegate open.
In other words, lets say that at 2psi of boost, the sensor sends 10mA and at 5psi (which i think is max) it sends 20mA. The ECU sees 20mA and opens the wastegate. So we build circuitry that continues to send 10mA until say 10 psi of boost. Then it sends 20mA.
Maybe. I have no idea how automotive electronics work at this level but...I do own a small electronic biz that designs and manufactures prototype circuit boards. If someone can figure it out, I'll make em for cheap.
That's if it would work!