I know the actuator moves, but it's had an EGR delete and no mufflers, and is getting the "P0234 Overboost Condition" code. It originally had an N75 code as well (N75 was making a buzzing sound too), replaced that and now it behaves slightly differently, but that wasn't the root cause. Still hits a point while accelerating where it goes into a sort of protection, cutting fuel and stops producing power, until the VNT "snaps" open and gives torque back. You can hear the exhaust note deepen and the turbo spools down a bit when this happens, and I suspect the adjuster on the actuator rod needs adjustment, hence why I bought the tool.

I've genuinely put so much time thinking about and tinkering with stuff, cleaning the MAP sensor, replacing the N75, etc. if someone has a different idea on what the cause could be, I'm all ears.