So far no enemy faction dared to attack Mon Cala despite its cut off location. The additional Invincible-class Cruisers I built there might have something to do with it. As long as it remains in my hands Mon Cala will still present a thorn in the Confederate side though and I hope it'll deter the AI from massive multi-pronged attacks on the Core Worlds. If I have some extra money left I'll slowly reinforce its Defense Fleet with one ship at a time to possibly deter the CIS for a while longer.