I would figure you simply break it down into three components. Front end (presenters) middle (plugin's) and back end (managers). The managers know nothing of th

I would figure you simply break it down into three components. Front end (presenters) middle (plugin's) and back end (managers). The managers know nothing of the front end and the presenters know nothing of the managers. That way you can always swap out your UI for a different one, right? If this is the case then you should develop the plugins first.