Some items that are scope=1 or scopeArsenal=1 will not be displayed and, in fact, be removed from loadouts edited with Arsenal. For example, editing an ammo bearer will remove its backpack because said (pre-packed) backpack is scope = 1. The same is true for uniforms that are "re-used" uniforms from another faction, i.e. CUP contains clothing for the Takistanis that is shared among factions, and to avoid showing double in the Arsenal the Independent versions are scope = 1.
While it obviously is not a good idea to make all scope = 1 items available, Arsenal should, wen it is launched record all items with scope = 1 that are in the current loadout and retain those items.