I don't know if I'll be at DSC this year or not. If I make it, I'll be at the Heym booth, and I'll bring one. I'm one of the founders of a group that's conducting a hunt that starts the last day of the DSC show, so DSC is kind of tight for me. If you'll please PM me a week or so before the show, I'll be able to give you a better answer.

Generally no, magazine rifles don't have anything like the problems with monos that doubles do, as min wall is much thicker. I HAVE heard of bolt rifles showing OSR, but have not seen one myself. I think it must be quite rare in single barrel rifles, but it would certainly depend on barrel profile.