Seems like everyone is making Freecoasters now and Primo joined the club as well. For the Freemix freecoaster they tried to come up with a minimal design according to their website and even added some hub guards. Those might come in handy for your next street flat adventure ;-) Here are some details from the Primo website:
"Our first freecoaster hub in a very long time the FREEMIX will be available next month and we figured this would be a good time to talk a bit about it. Our goal with this hub was to make the most basic coaster possible because as many of you may already know these hubs can be a bit confusing once disassembled. This is why our coaster come with no adjustable slack. By removing any adjustable pieces you are left with a longer lasting hub that requires less maintenance. The second detail we felt was very important was to offer the FREEMIX as a complete wheel as well since we know how inconvenient it can be building up a whole new wheel just to see what coasting feels like. If that's not enough for you we have a special treat to top it all off. If you are serious about wanting to get into riding a coaster do your research, the FREEMIX has been tested by nearly the entire Primo Pro team for over a year now and has been put to work."
You can see the Freemix Freecoaster in action in the Primo Blazers edit. A few more photos are available in the parts section: Primo - Freemix