In addition to the good suggestions offered by fellow monks, I would point out that your users might also appreciate a special tag to tell your code where to split the page.

This would allow your content-producers to insert this tag, let' s say a particular comment, in a place where it makes sense syntactically and semantically (instead of just syntactically). The way I see it, it could work like a very strong hint about where to break up the HTML.

Since I get from your post that your producers are thrust-worthy, this might add a lot of value to what you' re trying to achieve while keeping the risk of abuse to a minimum. Regards.