My experience is that Alaska does not do the best job tracking this kind of stuff... So I think you will find people who did not fly on an AS ticket but get miles and EQMs, sometimes without even checking in. It doesnt necessarily have to do with whether you check in or not. There is no method to the madness so I couldnt tell you how to guarantee it, but you can buy a full Y ticket and see... it is fully refundable whether you cancel it or not.