Where does the antimatter come from? Maybe the core has some collector for anti-matter, produced by small singularities in the universe. But because anti-matter decays - when they hit matter - there is not enough to continuously supply larger ships.
Producing anti-matter (fuel) may require the solar energy close to stars. Or stations with solar panels which don\'t use their thrusters all the time. Or can be found in some bigger anomaly.
this would make interior space necessary and require new blocks like ovens
If you just have a ship with 1 deck (3 blocks) which is 5 bocks wide and 7 blocks long, you need 3*5*2 + 3*7*2 + 5*7*2 elements - 30+42+70=142.
If you want it symetric and more than 10 blocks deko (like a separated cockpid room), it would add more than 15% to the mass!
This is not good for a ship with jammer. Any tower you engage will blast you to pieces.
Before we do this, we would need to have jammers/cloak count active (energy,shield,etc) parts differently from inactive (hull) or decorative (lamps/screens) parts.
Decorative elements (like lamps, screens, etc) in real life will never have the same weight as hardened armor of half your body\'s height.