It's cool to see this mod receiving an update! Thank you for your hard work.

My suggestion is that zombies cannot be changed by the mod unless there is no player within a certain distance from the zombie—maybe a configurable distance if you're feeling fancy. I propose this because, sometimes, a zombie near the player will suddenly transform into a sprinter after the player has already witnessed it and decided that he has time to turn his back on it. A courtesy distance would alleviate this issue by removing such surprises.