I believe the Readme out of date, (c.f. https://meta.stackoverflow.com/a/2678), and there are a number of missing exports, e.g no Tags export, so there is no link between Tag and Tag Wiki Post entities. There are also some semantic issues, such as migrated questions not being clearly marked up as such, and the fact that the post history appears to log both tag and body changes as 'Text changes'.
Is there any chance that the quality of the data dump could be addressed, at least in terms of completeness and consistency with the main SE dump?
Suggested tag: data-dump