I thought the idea of a roundabout was for traffic to proceed without coming to a total stop. I slow to almost a complete stop at roundabouts now because the only "near misses" I have had were recumbent bikes going full speed on the inside lane with a pennant the size of a napkin attached. I know they have the right of way but are almost impossible to see because of the vegetation. I drove a passenger shuttle at a large resort for 12 years, so I am especially careful.
IMO recumbent bikes should not be allowed on the main boulevards and roundabouts for safety reasons. There are plenty of other streets and trails for them to use.
Until then bikers, be aware that vehicle traffic may not see you and ride defensively.