The Linn integration works like a charm and as far as I can tell (after playing around with it for an hour or so) there are no issues. I am using a Linn Akurate DS (2010 variant) and did a software upgrade to 4.63.223 (which is a beta-release right now).
I have one question though. Is there a way to control the Linn device with my remote control to skip tracks, press play and pause ? I can do this when using the UPnP server but I was not able to do it with Roon.