Explorers are likely to want to take weapons and other combat equipment, such as chaff, SCBs, and heat sinks, or even fighters. They are going to need to resupply these if they do get into any combat with whatever is hostile out there.
Since they can already synthesise complicated ammo, or even AFMS ammo, it would also make sense to allow explorers to make the rest, including limpets. Have some true multi-role exploration vessels for a change. Might add some extra gameplay to find the right elements.