So it looks like my issue has finally been resolved!!!
The theory is that the T30 console bushes have the cutout in the rubber with the supporting solid part aligned with the load vector for a standard ride height. Lower the ride height and the load then goes through the soft part.
It doesn't show up when statically aligning the van but drive off and the slight toe in and uneven torque from the longer drive shaft pulls the wishbone forward, more so on the long drive shaft side. Thus the right side toes in more and pulls the van to the left.
Long story short, Ben at String Theory Garage has a resolution to this with the perfect setup so if you need your van sorting give him a call!
Mat