The now-defunct magazine, Pure Yuri Anthology Hirari, which solely published one-shots, released an anthology containing a selection of six of their one-shots:
To link the entries, you must be in the light novel entry and set Kono Subarashii Sekai ni Bakuen wo! as a 'spin-off'. The 'parent' relation will then be set in the opposite direction back to the light novel.
The light novel Mushoku Tensei: Isekai Ittara Honki Dasu was serialized in January 2014, and had a manga release, Mushoku Tensei: Isekai Ittara Honki Dasu, in May 2014, which is linked through the 'adaptation' relation. Two spin-offs, Mushoku Tensei - Roxy datte Honki desu and Mushoku Tensei: 4-koma ni Natte mo Honki Dasu, were then serialized in December 2017 and October 2018 respectively. Both spin-offs only branch off the light novel, and not the manga, so are only be linked to the light novel.