That boost surge is what you get when boost is controlled on the engine side of the throttle, moving the actuator pipe, or boost controller pressure sensor in your case, to the other side of the throttle would have made a big difference. (I'm guessing on the controller bit as most folks connect them like this, but the actuator pipe looked to be tee'd into the FPR ref pipe in your previous thread, so it's a iair assumption that the boost controller was the same)
Sorry mate. I must have missed this post at the time.
The boost controller is plumbed in EXACTLY how it was before (as far as I can tell anyway). The only difference being that it's now been mounted on the bulkhead next to the coolant bottle just to tidy the engine bay up a bit.