Simply make the default limit for Battlecruisers = 1. Nothing else needs changing!
The BC still remains a powerful flagship for your fleet, but now it is possible to disable and/or destroy it.
The real balance problem isn’t the first BC. The time/tech investment for it is balanced. The problem is the second and third BC (which are dirt cheap for the power they wield). Having a default unit cap of 1 fixes all of this.
In a fleet battle, it is now possible (and feasible) to attempt to disable a single BCs subsystems. When there were 3 BCs coming at you = what’s the point of losing a bunch of strikecraft/corvettes trying to slow down 1, when the other 2 will just get into range and kill you anyway! With just 1, subsystem/module attacks can now possibly change the outcome of a battle.
I know I’ve posted this idea in another topic, but I think it is such a simple (and effective) solution = I wanted to make sure the Devs saw it…