I think I found a bug with the Resources Needed tab.
Adding a Heat Vent to the planner costs 6 Iron.
Adding a Reactor Heat Vent to the planner costs 16 Copper and 6 Iron.
Adding an Overclocked Heat Vent to the planner costs 6 Iron and 2 Gold.
This implies that to make an Overclocked Heat Vent requires a Heat Vent and 2 Gold.
But on the server, crafting an Overclocked Heat Vent requires a Rector Heat Vent and 2 Gold.
So the true planner cost of adding an Overclocked Heat Vent should be 16 Copper, 6 Iron, and 2 Gold.