dry Ammonium Sulfate or ATS needs to be applied closer to when plants need the S as in side dress
Early spring Application of S in sulfate form will loose too much

Will you lose it even if you incorporate AMS within a few weeks?

This might be one of those controversial items like spreading DAP in the fall. Is the N from the DAP still there for the crop to use 6 months after over-wintering when you plant?