ohhhh, I *knew* I was forgetting something. I meant to make it so that springs couldn't spawn near the zone but forgot in the rush of the last few days. That said, even after taking some time this evening to mess with it, I realized that actually adjusting those numbers is a far trickier balancing act than I would have thought...
It's tough, because the fact that you *can* overshoot is part of what gives the game its depth, but if I had the energy to tinker more, I would probably have multiplied The Zone's size by 1.5 (after having already doubled it in the first place).
Still! I'm glad you enjoyed it, thanks for giving it a try!