Simple story is I was on a track day at Oulton Park on Tuesday, had a great time and car ran really well. In the afternoon I was seeing some blue smoke on the overrun, not all the time, just occasionally from high revs braking into the corners... Enough for the marshals to pull me at the end of the session and ask to check it wasn't dropping oil...So back to the pit garage had a look and found the turbo outlet pipe had oil running down onto the turbo, and the heat shield on the bulkhead to have oily mist around where the turbo sits.
.. 
You can see where the oil is on the turbo and heat shield.
So I'm thinking it might be that when the throttle is closed on overrun it is escaping through the outlet and spraying onto the heat shield, burning off on the turbo and shield.
There were maybe 3 or 4 drips on the garage floor when we were leaving.I know it could also be worn oil rings causing too much crankcase pressure but with the throttle being closed how could it make its way to the turbo.
..I've taken the pipes off this morning to check for shaft play and there isn't really any, no in out at all and very minimal play side to side, tighter than many Ive had previously.
Could the oil seals still leak even though there isn't any shaft play? More pics...
It doesn't really smoke on start up, or when driven normally.
And doesn't smoke on boost at all, only on over run from high revs on track. I haven't really seen any on normal fast road driving...