Hi BI,
Scripting missions is a challenge combining several scripts and editor. Could you imagine a multiple sheets of editing/previewing scenario while in the same mission? This could have the same effect of spawning groups, vehicles , hiding objects until triggered, without a line of script. A kind of chapters in the same mission, linked with an event (trigger or module, loops?) but easily accessible in the editor/preview mode. I don't know if this could lead to multiple mission1, mission2.sqm . The aim is to place all units in editor (at start && spawned) with a link between the sheets, keeping the benefit of less CPU/GPU resources.