There was a brief discussion here (Blogdown and Flexdashboard) about making blogdown and flexdashboards play nicely together, but the thread died without an obvious resolution. There are (apparently related) threads related to the use of iframes within the widgetframe package and htmlwidgets, but again, no clear roadmap for how to use the blog-down package to organize a set of flexdashboard outputs. Blogdown and htmlwidgets/and or blogdown and flexdashboards would seem to be a powerful combination.
I'd welcome any pointers to working examples, github repos or documentation that might clear the thicket of not-quite-on-target