Low boost high egts after high boost low egts

[Bidja]

But now I'm getting max 8psi boost and then cuts out after cruising at 100 for about 5 seconds and just sits at 0 before I take my foot of then back on and we repeat the process and the egts head north of 600 degrees.
Mods. egr blocked with 8mm hole, 3" exhaust, catch can, aftermarket intercooler, 33" tyres

Sounds like hard Limp to me.
Noted you blocked EGR when and maybe this cause the issue?
Why use blocking plate withe a hole _ defeats the purpose. Plate/EGR block may be impacting MAF volts signal to ECU. Remap is the best option (turn EGR function off).
Normal accepted practice with EGR block is to install manual boost control to eliminate spiking.

Concerned with 60-70kPa (18-20"Hg) vac at actuator to lift rod (lever to vane limit stop) can cause it to be very laggy (normall 13-14 "Hg).
Has the actuator rod length been changed?
Does the paint marks across actuator arm frame and adjuster thumb wheel line up?

If you wish to continue with VNT Vacsol / ECU control check that it is connected right. The sketch is a guide and the damper can also be fitted between vacsol and turbo actuator diaphragm.