We're planning on adding regulations and statutes, and the annotation platform should generally work for these texts as well. As you noted, there's a version control issue, and we're still thinking about the best way to deal with it. One possibility would be to have the text appear as a redline, which would make keeping all annotations alongside the text possible. Alternatively or in addition, we could have a revision history of the text (allowing you to view and compare older versions) -- then, the easiest way to manage annotations might be to keep annotations for paragraphs that haven't changed in the newer version, but to have annotations for changed paragraphs only appear in the older versions.