That whole setup is a farce. Earlier this month I was on MUC-OSL-KRS on one ticket and the gate wouldn't open. The girl tried to explain me that 'BP is from Lufthansa, only SK & DY allowed! SAS and LH are not the same, your flight is by LH!'
I offered to reprint my BP on SAS paper at the machine installed next to the gates, and she actually prevented me from doing so. 'will not work, you are flying Lufthansa!'
Tomorrow I'm doing MUC-OSL-BOO, and preemptively printed the BP for OSL-BOO on SAS.no using OLCI. Lets see if the gates work. I have two hours in OSL, so avoiding the hassle of security is nice, but not a must.