I’m not sure, but it sounds like you’re asking 2 questions. Setting the set screw is technically tricky. Setting the actuator is easy and VW suggests 3-5 inHg for starting to move and 17-20 inHg for when it stops and the vanes are wide open. If the movement is opposite of this, then swap the numbers.
The simple and semi-crude way to set the stop screw is to do an a-to-b pressure differential check between idle and 1400 RPM. On a 2.7l, where this turbo came from, your volume of air is significantly greater than on a 1.9l at both of those test points. If test procedure matches each other between the two engines, then you technically need to bump it to 1275 RPM & 2000 RPM for a 1.9l running a 2.7l turbo. Pressure differential should be 140 mbar, iirc, idealy? There is a specified range.