It was awhile since the last version of the my modded edition of HeadScape plugin. And this new gdHeadSpace4 4.1 one ads few custom post types related features (support for archives, embedding meta boxes) and it has several very important bugs fixed with meta tags rendering.
Page tag for the meta elements rendering was broken, and some post type related functions were missing. That is fixed now. Meta box for posts belonging to custom post types is added. Support for archives for custom post types is also included.
Initial release post:
http://www.dev4press.com/2010/blog/development/modded-plugin-headspace2/
gdHeadspace4:
http://www.dev4press.com/plugins/gd-headspace4/
Original Headspace2:
http://wordpress.org/extend/plugins/headspace2/