I really think that Extreme Capacitors need to be directly coolable, or at least let something other than Heat Inlets take heat from them. Currently they take up a LOT of space to get working without overheating either themselves or the reactor, leaving little room for power production -- meaning we can't even use them for the reason they were implemented, to be able to produce more power without wasting since we can't even reach that level with what room is left after stabilizing the capacitors.
Heat Vents don't seem to be cooling as fast as they say they do, as a Vent that cools itself by 32.89B heat each tick can't take the entire focus of a single Quad Dolorium cell feeding it 8.17B Heat per tick.
It makes it quite hard to figure out exactly how many vents one would need for safe idle-cooling of a new tier of cell without fooling around and experimenting possibly dangerously...
On a different note, I'm not sure if it's intended or not, but you can manually vent heat from the reactor while it's paused. I feel like that's a little bit cheaty.
Other than those gripes, still loving this!