It’s true that 1m3 is 1m3, but from a balance standpoint 1m3 of ore is way less valuable than 1m3 of the refined ore. Ore usually refines down to just a fraction of its source worth of minerals.
It’s kind of like: Which is worth more? 1kg of gold, or 1kg of feathers. They both weigh 1kg, but one’s worth more.
This did however give me a good idea for a potential solution to this using a rig. This rig could allow you to change one type of hold to another, but at a loss. So you can do something like turn ore, PI or other h old to a standard cargohold, but get a fraction of the space. Say 50% of special cargohold reduced and turned into 25% larger main cargo bay. Perhaps hull hp, mass, and/or inertia modifier can be adjusted as additional penalties to trade-off if needed.
This would unfortunately still leave most of the specialized haulers haul less than the generic, but can allow to take advantage of special features of some lines, like the drone bay on the Nereus.
Where this could really shine though would be with things like Orca, Bowhead, and Rorqual. Say you could reduce ship maintenance bay by 50% in exchange for a lesser amount of cargo bonus, either regular or Ore.
This could cause the Orca to be used in more places than the Freighter, but if limited to Ore, which the mining of is the Orca’s primary purpose, I don’t see a particular problem with having a similar relation to a freighter as a Kryos to an Iteron mk5.
One could even go further and make a new modular freighter or industrial command ship for each race designed to operate similar to the T3 destroyers where you can choose a mode (but presumably only in station or with refitting service) and put it into a mode where it optimizes cargo for different purposes, such as ship maintenance bay focus, ore focus, mineral focus etc.
There’s several ways that can give players more control over the focus of their industrial ships, and I’m sure there are even many that I haven’t suggested, but I do strongly feel that it would be nice to allow players more customization on their ship’s roles.