So a little update, I have driven around 250 - 300 miles with Forte seal conditioner in and it has not made any difference. I have also been carrying out a few other tests.
These are,
Cold start after the car being sat for 5 days. No smoke on start up
Long period of idle ~ 20 min from cold, then driven off. No smoke
Long period of idle ~ 20 min after 1hr drive then drive off. No smoke
Engine brake down long hill in 3rd, 4th, 5th gears drive after. Large plume of bluey white smoke that lingers and smells of burnt oil
Coast down same hill with clutch in then drive after. No smoke
Does this still sound like turbo oil seal?