All right, I think I misunderstood your issue the first time, but this screen capture certainly is worth a thousand words.
1) is not persisted upon exiting
2) is clamped, so should not go overboard
I suspect here this is not related to the zoom level but rather a visual glitch. Time for investigation on our side!
Could you please tell us which Chromebook you are running Sacrifices on and which version of the game you are playing?