Simple URLs are Duplicate Content
This is a problem for SEO. While Simple URLs are quite nice for SEO on their own, the non-simple URLs still work and go to the same content. This creates duplicate content (a second URL with the same page content) for every single article title. This results in a negative effect on the pagerank of each of the copies.
This is fixed for the next build by using a 301 redirect for the non-simple URLs if simple URLs are enabled. Since this is not possible via htaccess (because of the other necessary VaultWiki rules), this must be done via PHP by comparing the URL of the requested page against the simple URL of the requested page. Generated links using autolinks or wiki link BB-Codes already check for this.