What I'd personally like to see as an modding option is to have any cargo over your maximum be automatically dropped into space.
So, when the TCN is firing on you for having illegal cargo, they'll eventually hit your cargo bay, your capacity will drop and the contents will spill out.
Once the illegal goods are forcibly removed, they'll move on.
This would work awesome for pirates, too, if illegalness was not universal, but depended on the race. Pirates would consider trade goods and any other items of value, illegal. They'd then attack you until your cargo leaked out, upon which they'd steal it away and leave to sell it on the black market.