[2.2.12 pre1] MT_HIDDEN_SLING has issues with linedef type 442 in Binary maps
The "Change Object Type State" linedef type doesn't seem to change MT_HIDDEN_SLING's state when the linedef's backside textures are left blank. This bug was discovered in SRB2 The Past and my Retro Bosses addon for the Eggscalibur (2.1 Egg Colosseum). Both addons use a custom object which "clones" the MT_HIDDEN_SLING object, and it has the same issue.
2.2.11:
2.2.12 pre1:
From my testing, this bug only affects Binary maps.
(Shoutouts to U.Flame on the SRB2 Discord server for discovering this bug, and Glaber for bringing it to my attention)