Hi guys. Got a problem with my cvh turbo engine in my s2. Its running p8 cosworth management with siemens injectors and hybrid t34 turbo. The bottom end has been rebuilt ( all forged internals, new rings , rods etc ) and was sent away to get set up. Ive put millers running in oil and done about 5 miles in laps on the engine round my land a few times ( not mot'd so cant use roads due to restoration ) but once the engine is warm, theres blue smoke from the exhaust. On driving, it boosts fine in second ( new engine so cant blast it ) and only able to use first 3 gears due to space. Ive removed the air filter and theres a small bit of oily residue on the compressor housing by the turbine wheel, also slightly oily in intercooler and pipe coming from there to turbo housing. Now if i boost it, it doesnt really smoke much ( not sure if its cos smoke gets blown clear as i drive ? ) . If i go down the hill and hold in the clutch pedal it wont smoke.. When i rev around 2k on spot it will blatantly smoke. Ive changed the valve stem oil seals. There is side to side play in the turbo and a little in and out play. Now can anyone help with any ideas whats causing it. Does it sound like a dead turbo ? Or oil piston rings ? Ive been told that i need to take it for a long drive to bed the oil rings in and the smoke will eventually clear ?

edit, spark plugs are black, sooted. Also, i previously had an old turbo that failed and dumped oil in to the exhaust, removed system, tried to jetwash clear.
Any help appreciated, cheers