"Faster Mob Spawner Rates" civ perk - does not display in GUI (perk may or may not work)

If you place a spawner, regardless if it's placed in civ land or not, the GUI (Shift-click a spawner) shows the same values for Minimum spawn time Maximum spawn time Minimum number of mobs spawned Maximum number of mobs spawned regardless if you place the spawner in civ land or not. I'm not sure if the civ perk doesn't work, or if this is purely an issue with it not being displayed in the GUI