No, I don't see why milfoil needs to be killed. It's one of the most beneficial weeds in stained water systems. The drawdown could clean off some of the gravel areas for walleye spawning though. It's a trial and error thing. Not the best year for trial and error with this extreme winter. I'm guessing another bad winterkill year. Crane lake could be bad and the aeration system the DNR put in doesn't work.