Potentially, both Catchall page and Microsite can be served by a single Page Content Type. They are both one-page, one-off pages that potentially has content from CMS and/or custom code. Microsite is more structured with the navigation and potential sponsorship opportunities compared to Catchall page. In a way, Microsite is containing sections divided with navigation as their titles, and each section has the same capability that Catchall page has.

Thus, the unified content type would have a Type selector, which would display additional sections and fields for the navigation and sponsorship upon selecting Microsite option.