This is properly for later when inventories become available but I already have a case with the railgun and its large missiles. So a some way to transport these large items is needed either by large robotic conveyor transport system or robots. Having crew transport fractions isn't reasonable in my opinion.
Also it would be nice if there's an option to merge item parts. For example the Abh reailgun missile is made up of two parts, warhead and rocket motor, and these are stored separately.
