A leaked IMAX scene from Batman v Superman: Dawn of Justice suggests that the Ultimate Edition was originally set for a theatrical release.
Update: The IMAX ending of BvS‘ Ultimate Edition has now also appeared online, which you can watch in its 13-minute glory below.
The Ultimate Edition eventually came packaged with the Blu-ray and added an extra 30 minutes to the film, including deleted scenes and extensions of certain beats.
An IMAX version of the Ultimate Edition’s Knightmare sequence has emerged online, which you can watch below.