Most of these high end hoppers, like the Rotor etc, split in 2 so you can access the feed mechanism.
Why not simply design a new top shell that will fit on to an existing feed system?
since it doesnt need the capacity it will be lower profile.
Then you can switch between a high capacity loader for electros and a small capacity loader for pump/limited semi in less than 1 minute without having to remove the hopper from your marker.
the only over head would be the design of the new mold for the top shell