Grunts and bleats are an essential part of a deer's vocabulary. I tend to use both pre,peak and post rut. Whos to say that one buck is rutting heavialy while another is not? I dont think there's any harm in using them regardless of the rut condition. A deer is either receptive to it or not and I dont feel that a deer will be spooked or put on edge if it hears it and he's not in full rut. If that deer isn't rutting then it will most likely ignore what it hears and continue on it's way.