IFR A/C departing South and cruise alt above 15000 From KPAE – I hold on to these and treat them the same as departures from KSEA, departing the Tracon at 15000 or close to the border(they are NOT in the SHELF)
. For a smooth transition from climb to cruise, I usually handoff to CTR at about 12000 or within 5 miles of the Tracon Border (whichever comes first) or, to unicomm.
From KOLM – I hold on to these and hand them to CTR/Unicomm at about 6000 or close to the shelf border (for the same reasoning) (IN the SHELF) not above the 8999
IFR A/C departing North and cruise alt above 15000
From KPAE – I treat them the same as the above South bound from KOLM (IN the SHELF = not above 8999)
From KOLM – I treat then the same as the above South Bound from KPAE (they enter the TRACON)
I hope this makes sense?
Happy controlling

Peter