Sounds like a ring fault you got there. You say theres no smoke when you fire up, if thats the case then that tells you the valve seals are not leaking oil down the valve stems and guides after shutdown in to the top of the cylinder so when you start up that oil deposit on the piston burns off (ie burning blue)on start ups. So that can leave two other options, your compression rings are leaking allowing crankcase presser to build witch in turn can cause leaks,oil in the air filter (ie compression blow by) there is a certain amount of crankcase through when running.
The other is oil rings. You would not necessary see smoke on start up. What can happen the crankcase presser can force the oil past the rings and the oil left on the cylinder wall will burn off through exhaust.This you can't all ways see eather, especially at the early stage of wear.
There is a way to check. Have some one ride behind you and run as normal have the follower watch your exhaust crack it now and then also pulling off from lights gear changing etc. see if there's any puffs of smoke. This may be wear the 1000mi quart may be going. Hope this is of some use.