I've realized there is something else in SHIV that I have always wanted - optional variable tonnages for ships (a value which can be customized). Check the .cfg for each ship.
Some warships don't have it, as it would be unnecessary for them.
Hats off to the dev team (at least for me) for including this feature, assuming that is what it actually is - I might be wrong. Now, if I can only get my bonus materials...