Duke 3D: Viewscreens cannot be remotely triggered
The viewscreens shown in the video by design cannot be activated by the use key, but instead are supposed to display their camera image while the player stands in range. This broke with SVN revision r4679 (commit 27bc4811), and affects every renderer. (Thanks to Hendricks for providing missing synthesis builds)
According to High Treason this is not a commonly used feature, but it did exist in DOS Duke 3D.
Map file for testing: ___scrn2.map