I haven't noticed a problem. When the ball gets rolling I'm super hard to stop.
There's actually a better way as a warmonger though: Take most of an AI's cities and vassalize them while they still have a capital. You'll easily win culture or diplomacy that way, while avoiding combat penalties and having better diplomacy. Only reason to take capital is important wonders.
I mean it's unintuitive that not taking a capital can make more sense as a warmonger, but thems the ropes.
If I was going to make a change I'd make the penalty much smaller but per city taken. That would make sense to scale on mapsize like this cost used to, (Conquest is easier -> harder on map-size) and make razing more appealing. Problem is that I don't know if you can go below a single % with the CS changes, as the per city penalty would probably be: 4% on Duel, 2% on Tiny, 0.75% on Small, 0.5% on Standard, 0.35% on Large, 0.25% on Huge.
That, or make it 1% on small, 1% per 2 on standard, 1% per 3 on large, and 1 per 4 on huge. Not sure how the coding works.
@Gazebo is any of this feasible code-wise? I don't want to waste time discussing it if it's not.