Puff of blue smoke when shifting out of boost...

[Frizodanizzo]

Occam's razor... What was the very last thing you touched before the problem started. Could be the dipstick seal, oil cap seal. Or it could be the rupture disc in the valve cover.

Or PCV related.... It's probably not something too serious. Any of these above issues will pull oil through the compressor.

Last thing worked on the sonic I have was the valve cover being replaced for the bad disc in the pcv. Ever since it came out of the shop it blows blue smoke letting off the throttle after you can hear the turbo spin at a decent rate. Put around town no smoke at all.