Simple question from someone who knows next to nothing about wormholes, do the mass restrictions count items in the cargo hold or just the listed mass of the ship with whatever mass modifiers it has? Like if I, hypothetically, had 2000 mass in a ship hold of a ship that is 3000 mass, would it count as 5000 or just the 3000? Apologies if I worded this wrong.
The Mass listed in the fitting window is counted. Nothing else.
Ship mass is the only thing that counts. You can modify ship mass with certain equipment (higgs rig and an active afterburner or microwarp drive most notably, a special module for heavy interdictors, and armour plates also add a little mass) but that’s it. It doesn’t count your cargo weight.