Last month I wrote about improvements to Weston's Wayland back-end to better support this use-case of running Weston inside an existing Weston instance or running Weston atop another Wayland-based compositor. Now Jason Ekstrand is out this week with another round of fixes and new features.
The new features in this latest set of six Weston compositor patches come down to adding scale and full-screen options. The full-screen support handles either a --fullscreen switch or pressing CTRL + ALT + F when an output has focused. The other changes in this patch round are killing off unused output handling code, fixing cursor coordinate transforms, and moving around the configuration file parsing.
For more information on the latest work by Jason, see this mailing list thread. As another use-case for nested Wayland compositors, see the information towards the end of the Wayland DRI PRIME article.