It is still only a test set up, thus only inbounds on SK and DY metal are included if you have luggage. Flights from MPX and ARN on SK and DY and SK are covered, as well as MUC on DY.
I can confirm that there is no problems in passing through on a LH-issued boarding pass, as long as the arriving metal/origin is covered. Two days ago we flew MUC-ARN-OSL-KSU on a SAS issued ticket, but with a LH issued boarding pass, and that was accepted by the machines. I have also travelled LHR-OSL-TRD with hand luggage only (SK/SK) and could pass through with no issue. How a LH/SK through ticket would work I do not know.
But do remember that Connecting Norway is still in a test period.