I have many Arsenal saved profiles and some of them can be loaded even if they contain gear that is not listed in BIS_ADDVIRTUALWEAPONCARGO_CARGO variable while playing a mission.
The following commands are used to open Arsenal in the test mission:
BIS_ADDVIRTUALWEAPONCARGO_CARGO = [_items_allowed, _weapons_allowed, _magazines_allowed, _backpacks_allowed];
["Open", [false, objNull, _soldier]] spawn BIS_FNC_ARSENAL;
Note: launching Arsenal with following method yields same result
tmp = [_items_allowed, _weapons_allowed, _magazines_allowed, _backpacks_allowed];
["Open", [false, tmp, _soldier]] spawn BIS_FNC_ARSENAL;