[Plugin: WordPress SEO by Yoast] Page with Advanced > 301 Redirect URL not in page-sitemap.xml

WordPress version: 3.4.1
WordPress SEO version: 1.2.8.4

In order to create a menu item that goes straight to an html page outside of my wordpress install, but on the same domain, I created a blank page and gave it a WP title/permalink and in the WordPress SEO by Yoast > Advanced section, specified the 301 Redirect URL.

I expected the plugin to make an entry in the page-sitemap.xml for this page.

Instead, neither the page permalink or the 301 Redirect URL are added to the sitemap. I tried settings:
Include in Sitemap: Always include and
Sitemap Priority: 1 – Highest priority
…but the page is still not included in the sitemap. Am I missing something? Is it designed to include either of these?

See site at travelswithmyhat.com, the page in question is “Book Preview”

Cheers
Rosie
(re-posted as topic truncated first time round…)

http://wordpress.org/extend/plugins/wordpress-seo/