What options are out there for a late season bean pre that leaves the options open to go to a Wheat or Cereal Rye cover crop post harvest? It seems like just about everything has a 4 month rotational limit on it. How strict is that window assuming plenty of moisture is coming?

The field is clean but needs sprayed now or I can almost guarantee a water hemp flush will happen in the next few weeks. I'd rather prevent it instead of trying to clean it up when it happens with Cobra as they don't need to be set back unless absolutely necessary. Water hemp is really the only concern. Any suggestions?