I think that is a good solution.

There is still the matter of how to get the content item **with** its latest revision for the UI. A separate HTTP request, or maybe handle the fetching of both the content profile and latest revision in the REST endpoint? My vote I think is on making the REST endpoint smart enough to do it, assuming that pretty much every time we fetch `/api/content/<contentId>` for a collabdoc we'll want the latest html with it as well.