How high are the decompression zones supposed to be? Do they reach "through" things that pass over/through them or are they clipped like smoke? I can't seem to find anything about it. The ones in TTS are 8", but I don't know where they got that from.
See the main rules for terrain zones on https://infinitythewiki.com/Terrain_&_Scenery_Structures In game terms, Special Terrain areas have infinite height unless otherwise specified.
Can a TO make the decision to reduce the number of decompression zones players deploy for a mission? I. E. From 2-1. Would such a decision invalidate/delist a tournament?
ITS already allows TOs to include one custom mission per tournament, which can include completely custom missions or altered existing missions. But this isn't checked or policed, so TOs could change more than one mission if they felt like it.